diff --git a/docs/src/generated/node-v24-compatibility-meta.json b/docs/src/generated/node-v24-compatibility-meta.json
index 28a4cdd8b..b507d1988 100644
--- a/docs/src/generated/node-v24-compatibility-meta.json
+++ b/docs/src/generated/node-v24-compatibility-meta.json
@@ -2,6 +2,6 @@
   "schemaVersion": 3,
   "nodeVersion": "24.15.0",
   "nodeCommit": "848430679556aed0bd073f2bc263331ad84fa119",
-  "artifactVersion": "11c3ebd9479ef9f7eca0",
+  "artifactVersion": "382e8ff3544e0a3e29a8",
   "rowCount": 3662
 }
diff --git a/docs/src/generated/node-v24-compatibility.json b/docs/src/generated/node-v24-compatibility.json
index 4471c5305..3468361c2 100644
--- a/docs/src/generated/node-v24-compatibility.json
+++ b/docs/src/generated/node-v24-compatibility.json
@@ -1067,9 +1067,9 @@
       },
       "dynamic": {
         "supported": 0,
-        "partial": 10,
+        "partial": 22,
         "refused": 0,
-        "not-implemented": 15,
+        "not-implemented": 3,
         "by-design": 0,
         "unreviewed": 0,
         "not-applicable": 0
@@ -44567,7 +44567,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "detail": "Provided when the embedded npm module bootstrap runs; absent from standalone dynamic islands.",
+        "detail": "Provided by the embedded engine's web/global compatibility layer.",
         "verification": "test-backed"
       }
     },
@@ -44707,7 +44707,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "detail": "Provided when the embedded npm module bootstrap runs; absent from standalone dynamic islands.",
+        "detail": "Provided by the embedded engine's web/global compatibility layer.",
         "verification": "test-backed"
       }
     },
@@ -78240,7 +78240,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "detail": "Available through the embedded Node compatibility shim; exact member and overload coverage may be narrower.",
+        "detail": "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.",
         "verification": "test-backed"
       }
     },
@@ -78268,7 +78268,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "detail": "Available through the embedded Node compatibility shim; exact member and overload coverage may be narrower.",
+        "detail": "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.",
         "verification": "test-backed"
       }
     },
@@ -78296,7 +78296,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "detail": "Available through the embedded Node compatibility shim; exact member and overload coverage may be narrower.",
+        "detail": "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.",
         "verification": "test-backed"
       }
     },
@@ -78323,9 +78323,9 @@
         "verification": "registry-gap"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78351,9 +78351,9 @@
         "verification": "registry-gap"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78407,9 +78407,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78435,9 +78435,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78463,9 +78463,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78491,9 +78491,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78547,9 +78547,9 @@
         "verification": "registry-gap"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78575,9 +78575,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78603,9 +78603,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78631,9 +78631,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78659,9 +78659,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
@@ -78715,9 +78715,9 @@
         "verification": "test-backed"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "detail": "This API is not implemented by the dynamic-island shim.",
-        "verification": "registry-gap"
+        "status": "partial",
+        "detail": "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.",
+        "verification": "test-backed"
       }
     },
     {
diff --git a/internal/compatibility/dynamic-support.json b/internal/compatibility/dynamic-support.json
index 7248b78dc..a6d83d7ff 100644
--- a/internal/compatibility/dynamic-support.json
+++ b/internal/compatibility/dynamic-support.json
@@ -19,6 +19,8 @@
     "wasi": "by-design"
   },
   "features": [
+    { "chapter": "timers", "symbols": ["timersPromises.setTimeout", "timersPromises.setImmediate", "timersPromises.setInterval", "timersPromises.scheduler.wait", "timersPromises.scheduler.yield"], "status": "partial", "evidence": ["tests/fixtures/npm/cases/node24-promise-timers/main.ts", "tests/fixtures/npm/cases/node24-timers-unref/main.ts"] },
+    { "chapter": "timers", "symbols": ["immediate.ref", "immediate.unref", "immediate.hasRef", "timeout.ref", "timeout.unref", "timeout.hasRef", "timeout.refresh", "timeout.close"], "signatures": ["`immediate[Symbol.dispose]()`", "`timeout[Symbol.dispose]()`"], "status": "partial", "evidence": ["tests/fixtures/npm/cases/island-timers/main.ts", "tests/fixtures/npm/cases/node24-promise-timers/main.ts", "tests/fixtures/npm/cases/node24-timers-unref/main.ts"] },
     { "chapter": "events", "symbols": ["events.once", "events.on", "events.addAbortListener"], "status": "partial", "evidence": ["tests/fixtures/npm/cases/node24-async-events/main.ts"] },
     { "chapter": "events", "symbols": ["emitter.on", "emitter.addListener", "emitter.once", "emitter.prependListener", "emitter.prependOnceListener", "emitter.removeListener", "emitter.off", "emitter.removeAllListeners", "emitter.emit", "emitter.listenerCount", "emitter.eventNames", "events.errorMonitor"], "status": "partial", "evidence": ["tests/fixtures/npm/cases/stream-shims/main.ts", "tests/fixtures/npm/cases/node24-event-emitter/main.ts"] },
     { "chapter": "util", "symbols": ["util.promisify", "util.callbackify"], "status": "partial", "evidence": ["tests/fixtures/npm/cases/util-shims/main.ts", "tests/fixtures/npm/cases/node24-util-adapters/main.ts"] },
@@ -91,8 +93,8 @@
     "util/types": { "exports": ["isAnyArrayBuffer", "isArrayBufferView", "isArgumentsObject", "isArrayBuffer", "isAsyncFunction", "isBigInt64Array", "isBigUint64Array", "isBooleanObject", "isBoxedPrimitive", "isBigIntObject", "isCryptoKey", "isDataView", "isDate", "isExternal", "isFloat16Array", "isFloat32Array", "isFloat64Array", "isGeneratorFunction", "isGeneratorObject", "isInt8Array", "isInt16Array", "isInt32Array", "isKeyObject", "isMap", "isMapIterator", "isModuleNamespaceObject", "isNativeError", "isNumberObject", "isPromise", "isProxy", "isRegExp", "isSet", "isSetIterator", "isSharedArrayBuffer", "isStringObject", "isSymbolObject", "isTypedArray", "isUint8Array", "isUint8ClampedArray", "isUint16Array", "isUint32Array", "isWeakMap", "isWeakSet"], "evidence": ["tests/fixtures/npm/cases/util-shims/main.ts"] }
   },
   "globals": {
-    "supported": ["atob", "btoa", "clearInterval", "clearTimeout", "queueMicrotask", "setInterval", "setTimeout", "structuredClone", "AbortController", "AbortSignal", "Blob", "CustomEvent", "DOMException", "Event", "EventTarget", "File", "Headers", "MessageChannel", "MessageEvent", "MessagePort", "Request", "Response", "TextDecoder", "TextDecoderStream", "TextEncoder", "TransformStream", "URLSearchParams", "ReadableStream"],
-    "npmSupported": ["Buffer", "URL", "clearImmediate", "setImmediate"],
+    "supported": ["atob", "btoa", "clearImmediate", "clearInterval", "clearTimeout", "queueMicrotask", "setImmediate", "setInterval", "setTimeout", "structuredClone", "AbortController", "AbortSignal", "Blob", "CustomEvent", "DOMException", "Event", "EventTarget", "File", "Headers", "MessageChannel", "MessageEvent", "MessagePort", "Request", "Response", "TextDecoder", "TextDecoderStream", "TextEncoder", "TransformStream", "URLSearchParams", "ReadableStream"],
+    "npmSupported": ["Buffer", "URL"],
     "absent": ["BroadcastChannel", "ByteLengthQueuingStrategy", "CloseEvent", "CompressionStream", "CountQueuingStrategy", "CryptoKey", "DecompressionStream", "EventSource", "FormData", "Navigator", "ReadableByteStreamController", "ReadableStreamBYOBReader", "ReadableStreamBYOBRequest", "Storage", "SubtleCrypto", "TextEncoderStream", "TransformStreamDefaultController", "URLPattern", "WebAssembly", "WebSocket", "WritableStream", "WritableStreamDefaultController", "WritableStreamDefaultWriter"],
     "evidence": ["tests/harness/web-globals.test.ts"]
   }
diff --git a/internal/compatibility/generated/node-v24-backlog.json b/internal/compatibility/generated/node-v24-backlog.json
index d661b6da9..747c2b9c5 100644
--- a/internal/compatibility/generated/node-v24-backlog.json
+++ b/internal/compatibility/generated/node-v24-backlog.json
@@ -14,8 +14,8 @@
         "implement": 81
       },
       "dynamic": {
-        "audit-partial": 816,
-        "verify-gap": 2222,
+        "audit-partial": 828,
+        "verify-gap": 2210,
         "replace-refusal": 112,
         "implement": 218
       }
@@ -45956,7 +45956,7 @@
           "action": "audit-partial",
           "verification": "test-backed",
           "confidence": "high",
-          "source": "island-npm-global:clearImmediate",
+          "source": "island-global:clearImmediate",
           "tests": [
             "tests/harness/web-globals.test.ts"
           ]
@@ -46144,7 +46144,7 @@
           "action": "audit-partial",
           "verification": "test-backed",
           "confidence": "high",
-          "source": "island-npm-global:setImmediate",
+          "source": "island-global:setImmediate",
           "tests": [
             "tests/harness/web-globals.test.ts"
           ]
@@ -86829,9 +86829,10 @@
           "action": "audit-partial",
           "verification": "test-backed",
           "confidence": "high",
-          "source": "island-export:node:timers/promises.setTimeout",
+          "source": "island-feature:timers.timersPromises.setTimeout",
           "tests": [
-            "tests/fixtures/npm/cases/misc-shims/main.ts"
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
           ]
         }
       }
@@ -86869,9 +86870,10 @@
           "action": "audit-partial",
           "verification": "test-backed",
           "confidence": "high",
-          "source": "island-export:node:timers/promises.setImmediate",
+          "source": "island-feature:timers.timersPromises.setImmediate",
           "tests": [
-            "tests/fixtures/npm/cases/misc-shims/main.ts"
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
           ]
         }
       }
@@ -86909,9 +86911,10 @@
           "action": "audit-partial",
           "verification": "test-backed",
           "confidence": "high",
-          "source": "island-export:node:timers/promises.setInterval",
+          "source": "island-feature:timers.timersPromises.setInterval",
           "tests": [
-            "tests/fixtures/npm/cases/misc-shims/main.ts"
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
           ]
         }
       }
@@ -86940,12 +86943,15 @@
           "tests": []
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timersPromises.scheduler.wait",
+          "tests": [
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -86973,12 +86979,15 @@
           "tests": []
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timersPromises.scheduler.yield",
+          "tests": [
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87044,12 +87053,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.immediate.hasRef",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87082,12 +87095,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.immediate.ref",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87120,12 +87137,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.immediate.unref",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87155,12 +87176,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.immediate",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87221,12 +87246,16 @@
           "tests": []
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout.close",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87259,12 +87288,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout.hasRef",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87297,12 +87330,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout.ref",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87335,12 +87372,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout.refresh",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87373,12 +87414,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout.unref",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
@@ -87445,12 +87490,16 @@
           ]
         },
         "dynamic": {
-          "status": "not-implemented",
-          "action": "verify-gap",
-          "verification": "registry-gap",
-          "confidence": "low",
-          "source": "island-unmatched:timers",
-          "tests": []
+          "status": "partial",
+          "action": "audit-partial",
+          "verification": "test-backed",
+          "confidence": "high",
+          "source": "island-feature:timers.timeout",
+          "tests": [
+            "tests/fixtures/npm/cases/island-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+            "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+          ]
         }
       }
     },
diff --git a/internal/compatibility/generated/node-v24-internal.json b/internal/compatibility/generated/node-v24-internal.json
index 737bbef7c..3191315df 100644
--- a/internal/compatibility/generated/node-v24-internal.json
+++ b/internal/compatibility/generated/node-v24-internal.json
@@ -1188,9 +1188,9 @@
       },
       "dynamic": {
         "supported": 0,
-        "partial": 10,
+        "partial": 22,
         "refused": 0,
-        "not-implemented": 15,
+        "not-implemented": 3,
         "by-design": 0,
         "unreviewed": 0,
         "not-applicable": 0
@@ -61878,7 +61878,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "evidence": "island-npm-global:clearImmediate",
+        "evidence": "island-global:clearImmediate",
         "tests": [
           "tests/harness/web-globals.test.ts"
         ]
@@ -62043,7 +62043,7 @@
       },
       "dynamic": {
         "status": "partial",
-        "evidence": "island-npm-global:setImmediate",
+        "evidence": "island-global:setImmediate",
         "tests": [
           "tests/harness/web-globals.test.ts"
         ]
@@ -104044,7 +104044,10 @@
         "status": "partial",
         "evidence": "derived:descendants",
         "tests": [
-          "tests/fixtures/npm/cases/misc-shims/main.ts"
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/misc-shims/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
         ]
       },
       "anchorSource": "chapter"
@@ -104375,9 +104378,10 @@
       },
       "dynamic": {
         "status": "partial",
-        "evidence": "island-export:node:timers/promises.setTimeout",
+        "evidence": "island-feature:timers.timersPromises.setTimeout",
         "tests": [
-          "tests/fixtures/npm/cases/misc-shims/main.ts"
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
         ]
       },
       "anchorSource": "exact"
@@ -104411,9 +104415,10 @@
       },
       "dynamic": {
         "status": "partial",
-        "evidence": "island-export:node:timers/promises.setImmediate",
+        "evidence": "island-feature:timers.timersPromises.setImmediate",
         "tests": [
-          "tests/fixtures/npm/cases/misc-shims/main.ts"
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
         ]
       },
       "anchorSource": "exact"
@@ -104447,9 +104452,10 @@
       },
       "dynamic": {
         "status": "partial",
-        "evidence": "island-export:node:timers/promises.setInterval",
+        "evidence": "island-feature:timers.timersPromises.setInterval",
         "tests": [
-          "tests/fixtures/npm/cases/misc-shims/main.ts"
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
         ]
       },
       "anchorSource": "exact"
@@ -104476,8 +104482,12 @@
         "evidence": "compiler-unmatched:timers"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timersPromises.scheduler.wait",
+        "tests": [
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104503,8 +104513,12 @@
         "evidence": "compiler-unmatched:timers"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timersPromises.scheduler.yield",
+        "tests": [
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104563,8 +104577,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.immediate.hasRef",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104596,8 +104615,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.immediate.ref",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104629,8 +104653,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.immediate.unref",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104659,8 +104688,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.immediate",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104713,8 +104747,13 @@
         "evidence": "compiler-unmatched:timers"
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout.close",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104746,8 +104785,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout.hasRef",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104779,8 +104823,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout.ref",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104812,8 +104861,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout.refresh",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104845,8 +104899,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout.unref",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
@@ -104907,8 +104966,13 @@
         ]
       },
       "dynamic": {
-        "status": "not-implemented",
-        "evidence": "island-unmatched:timers"
+        "status": "partial",
+        "evidence": "island-feature:timers.timeout",
+        "tests": [
+          "tests/fixtures/npm/cases/island-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-promise-timers/main.ts",
+          "tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+        ]
       },
       "anchorSource": "exact"
     },
diff --git a/internal/compatibility/src/generate.mjs b/internal/compatibility/src/generate.mjs
index 3da1af5e8..7eb75c51a 100644
--- a/internal/compatibility/src/generate.mjs
+++ b/internal/compatibility/src/generate.mjs
@@ -678,6 +678,8 @@ function publicDetail(tier) {
     return "No dynamic-island implementation exists for this Node API family yet.";
   }
   if (source.startsWith("island-feature:")) {
+    if (source.startsWith("island-feature:timers.timersPromises.")) return "Provides cancellable promise timers, buffered interval iteration, scheduler waits and yields, and ref options over the native event loop; delay warnings remain outside this subset.";
+    if (source.startsWith("island-feature:timers.")) return "Provides timer and immediate handles with reference control, refresh, cancellation, and disposal over the native event loop.";
     if (source === "island-feature:events.events.once") return "Waits for EventEmitter or EventTarget events with AbortSignal cancellation, Node abort errors, and listener cleanup.";
     if (source === "island-feature:events.events.on") return "Iterates EventEmitter or EventTarget events with buffered delivery, close events, cancellation, watermark backpressure, and listener cleanup.";
     if (source === "island-feature:events.events.addAbortListener") return "Registers disposable abort listeners that run even when ordinary propagation is stopped; already-aborted signals schedule the callback in a microtask.";
diff --git a/packages/compiler/test/ts7/baselines/order-parity.json b/packages/compiler/test/ts7/baselines/order-parity.json
index 6cb4f3d91..456cdfffb 100644
--- a/packages/compiler/test/ts7/baselines/order-parity.json
+++ b/packages/compiler/test/ts7/baselines/order-parity.json
@@ -13426,6 +13426,18 @@
     "<repo>/tests/fixtures/npm/cases/node24-async-events/main.ts"
    ],
    "diags": []
+  },
+  "<repo>/tests/fixtures/npm/cases/node24-promise-timers/main.ts": {
+   "order": [
+    "<repo>/tests/fixtures/npm/cases/node24-promise-timers/main.ts"
+   ],
+   "diags": []
+  },
+  "<repo>/tests/fixtures/npm/cases/node24-timers-unref/main.ts": {
+   "order": [
+    "<repo>/tests/fixtures/npm/cases/node24-timers-unref/main.ts"
+   ],
+   "diags": []
   }
  }
 }
diff --git a/packages/runtime/src/scr_island.c b/packages/runtime/src/scr_island.c
index e6622a99b..27f818f9f 100644
--- a/packages/runtime/src/scr_island.c
+++ b/packages/runtime/src/scr_island.c
@@ -9459,9 +9459,8 @@ static const char isl_modules_bootstrap[] =
     "    c.default = c;\n"
     "    return c;\n"
     "  });\n"
-    /* node:timers (+ timers/promises) over the island's timer
-     * bridge; setImmediate rides a zero-delay timer (Node's check
-     * phase does not exist here — documented divergence). */
+    /* node:timers and timers/promises share the native timer heap and
+     * immediate queue through the web prelude's handle objects. */
     "  builtins.timers = memo(() => {\n"
     "    const t = {\n"
     "      setTimeout: globalThis.setTimeout,\n"
@@ -9475,30 +9474,94 @@ static const char isl_modules_bootstrap[] =
     "    return t;\n"
     "  });\n"
     "  builtins['timers/promises'] = memo(() => {\n"
-    "    const delay = (ms, value, options) => new Promise((resolve, reject) => {\n"
-    "      const t = globalThis.setTimeout(() => resolve(value), ms);\n"
-    "      if (options !== undefined && options !== null && options.signal !== undefined && typeof options.signal.addEventListener === 'function') {\n"
-    "        options.signal.addEventListener('abort', () => {\n"
-    "          globalThis.clearTimeout(t);\n"
-    "          const e = new Error('The operation was aborted');\n"
-    "          e.name = 'AbortError';\n"
-    "          e.code = 'ABORT_ERR';\n"
-    "          reject(e);\n"
-    "        });\n"
+    "    const resistant = Symbol.for('scriptc.events.resistStopPropagation');\n"
+    "    const checkDelay = (delay) => {\n"
+    "      if (delay !== undefined && typeof delay !== 'number') envArgumentError('delay', 'of type number', delay);\n"
+    "    };\n"
+    "    const checkOptions = (options) => {\n"
+    "      if (options === null || typeof options !== 'object' || Array.isArray(options)) envArgumentError('options', 'of type object', options);\n"
+    "      if (options.signal !== undefined) {\n"
+    "        const signal = options.signal;\n"
+    "        if (signal === null || typeof signal !== 'object' || !('aborted' in signal)) envArgumentError('options.signal', 'an instance of AbortSignal', signal);\n"
     "      }\n"
-    "    });\n"
+    "      if (options.ref !== undefined) {\n"
+    "        const ref = options.ref;\n"
+    "        if (typeof ref !== 'boolean') envArgumentError('options.ref', 'of type boolean', ref);\n"
+    "      }\n"
+    "      const { signal, ref = true } = options;\n"
+    "      return { signal, ref };\n"
+    "    };\n"
+    "    const abortError = (signal) => {\n"
+    "      const error = new Error('The operation was aborted', { cause: signal.reason });\n"
+    "      error.name = 'AbortError'; error.code = 'ABORT_ERR';\n"
+    "      return error;\n"
+    "    };\n"
+    "    const wait = (immediate, delay, value, options) => {\n"
+    "      let signal, ref;\n"
+    "      try {\n"
+    "        if (!immediate) checkDelay(delay);\n"
+    "        ({ signal, ref } = checkOptions(options));\n"
+    "      } catch (error) { return Promise.reject(error); }\n"
+    "      if (signal && signal.aborted) return Promise.reject(abortError(signal));\n"
+    "      let timer, onCancel;\n"
+    "      const promise = new Promise((resolve, reject) => {\n"
+    "        timer = immediate ? globalThis.setImmediate(resolve, value) : globalThis.setTimeout(resolve, delay, value);\n"
+    "        if (!ref) timer.unref();\n"
+    "        if (signal) {\n"
+    "          onCancel = () => {\n"
+    "            if (!timer._destroyed) {\n"
+    "              if (immediate) globalThis.clearImmediate(timer); else globalThis.clearTimeout(timer);\n"
+    "              reject(abortError(signal));\n"
+    "            }\n"
+    "          };\n"
+    "          signal.addEventListener('abort', onCancel, { __proto__: null, [resistant]: true });\n"
+    "        }\n"
+    "      });\n"
+    "      return onCancel ? promise.finally(() => signal.removeEventListener('abort', onCancel)) : promise;\n"
+    "    };\n"
+    "    function setTimeout(delay, value, options = {}) { return wait(false, delay, value, options); }\n"
+    "    function setImmediate(value, options = {}) { return wait(true, undefined, value, options); }\n"
+    "    async function* setInterval(delay, value, options = {}) {\n"
+    "      checkDelay(delay);\n"
+    "      const { signal, ref } = checkOptions(options);\n"
+    "      if (signal && signal.aborted) throw abortError(signal);\n"
+    "      let timer, onCancel;\n"
+    "      try {\n"
+    "        let notYielded = 0, callback;\n"
+    "        timer = globalThis.setInterval(() => {\n"
+    "          notYielded++;\n"
+    "          if (callback) { callback(); callback = undefined; }\n"
+    "        }, delay);\n"
+    "        if (!ref) timer.unref();\n"
+    "        if (signal) {\n"
+    "          onCancel = () => {\n"
+    "            globalThis.clearInterval(timer);\n"
+    "            if (callback) { callback(Promise.reject(abortError(signal))); callback = undefined; }\n"
+    "          };\n"
+    "          signal.addEventListener('abort', onCancel, { __proto__: null, once: true, [resistant]: true });\n"
+    "        }\n"
+    "        while (!(signal && signal.aborted)) {\n"
+    "          if (notYielded === 0) await new Promise(resolve => callback = resolve);\n"
+    "          for (; notYielded > 0; notYielded--) yield value;\n"
+    "        }\n"
+    "        throw abortError(signal);\n"
+    "      } finally {\n"
+    "        globalThis.clearInterval(timer);\n"
+    "        if (signal) signal.removeEventListener('abort', onCancel);\n"
+    "      }\n"
+    "    }\n"
+    "    const schedulerBrand = Symbol('kScheduler');\n"
+    "    const checkScheduler = (receiver) => {\n"
+    "      if (!receiver[schedulerBrand]) { const error = new TypeError('Value of \"this\" must be of type Scheduler'); error.code = 'ERR_INVALID_THIS'; throw error; }\n"
+    "    };\n"
+    "    class Scheduler {\n"
+    "      constructor() { const error = new TypeError('Illegal constructor'); error.code = 'ERR_ILLEGAL_CONSTRUCTOR'; throw error; }\n"
+    "      yield() { checkScheduler(this); return setImmediate(); }\n"
+    "      wait(delay, options) { checkScheduler(this); return setTimeout(delay, undefined, options); }\n"
+    "    }\n"
+    "    const scheduler = Object.create(Scheduler.prototype); scheduler[schedulerBrand] = true;\n"
     "    const tp = {\n"
-    "      setTimeout: delay,\n"
-    "      setImmediate: (value) => delay(0, value),\n"
-    "      setInterval: (ms, value, options) => ({\n"
-    "        async *[Symbol.asyncIterator]() {\n"
-    "          for (;;) {\n"
-    "            await delay(ms, undefined, options);\n"
-    "            yield value;\n"
-    "          }\n"
-    "        },\n"
-    "      }),\n"
-    "      scheduler: { wait: (ms) => delay(ms), yield: () => delay(0) },\n"
+    "      setTimeout, setImmediate, setInterval, scheduler,\n"
     "    };\n"
     "    tp.default = tp;\n"
     "    return tp;\n"
@@ -10050,15 +10113,9 @@ static const char isl_modules_bootstrap[] =
     /* Node's Buffer global (and `global` itself) — embedded CJS
      * reaches both without requiring anything. */
     "  globalThis.Buffer = builtins.buffer().Buffer;\n"
-    /* setImmediate/clearImmediate globals (zero-delay timers — no
-     * check phase in the island; documented divergence), and the
-     * global console upgraded to Node's util.format semantics for
+    /* The global console upgraded to Node's util.format semantics for
      * npm builds (the web prelude's String() console stays for
      * non-npm islands). */
-    "  if (globalThis.setImmediate === undefined) {\n"
-    "    globalThis.setImmediate = (fn, ...args) => globalThis.setTimeout(fn, 0, ...args);\n"
-    "    globalThis.clearImmediate = (t) => globalThis.clearTimeout(t);\n"
-    "  }\n"
     "  {\n"
     "    const fmt = (...a) => builtins.util().formatWithOptions({}, ...a);\n"
     "    const to = (fd, prefix) => (...a) => { host.write(fd, (prefix || '') + fmt(...a) + '\\n'); };\n"
diff --git a/packages/runtime/src/scr_web.c b/packages/runtime/src/scr_web.c
index 9751f1b66..73f619511 100644
--- a/packages/runtime/src/scr_web.c
+++ b/packages/runtime/src/scr_web.c
@@ -62,43 +62,77 @@ static const char web_prelude[] =
     "   * (host.setTimer/host.clearTimer) — REF'd like Node's (an armed\n"
     "   * timer keeps the process alive), FIFO-ordered against static\n"
     "   * timers on one heap, Node's <1ms clamp. Returns a Timeout-shaped\n"
-    "   * object (ref/unref/refresh/close, numeric via toPrimitive) that\n"
-    "   * clearTimeout/clearInterval accept alongside plain ids; unref is\n"
-    "   * accepted but not honored (the entry stays ref'd — a documented\n"
-    "   * approximation). */\n"
+    "   * object with real ref/unref/refresh/close operations. Immediates\n"
+    "   * use the native check queue, independently of timer ids. */\n"
+    "  const timers = new Map();\n"
     "  class Timeout {\n"
-    "    constructor(fn, delay, repeat) {\n"
+    "    constructor(fn, delay, args, repeat) {\n"
     "      this._fn = fn;\n"
     "      this._delay = delay;\n"
+    "      this._args = args;\n"
     "      this._repeat = repeat;\n"
-    "      this._id = host.setTimer(fn, delay, repeat);\n"
+    "      this._reffed = true;\n"
+    "      this._closed = false;\n"
+    "      this._callback = () => {\n"
+    "        if (!this._repeat) { this._destroyed = true; timers.delete(this._id); }\n"
+    "        this._fn.apply(this, this._args);\n"
+    "      };\n"
+    "      this._arm();\n"
     "    }\n"
-    "    ref() { return this; }\n"
-    "    unref() { return this; }\n"
-    "    hasRef() { return true; }\n"
+    "    _arm() {\n"
+    "      this._destroyed = false;\n"
+    "      this._id = host.setTimer(this._callback, this._delay, this._repeat, false);\n"
+    "      timers.set(this._id, this);\n"
+    "      if (!this._reffed) host.refTimer(this._id, false, false);\n"
+    "    }\n"
+    "    ref() { this._reffed = true; host.refTimer(this._id, true, false); return this; }\n"
+    "    unref() { this._reffed = false; host.refTimer(this._id, false, false); return this; }\n"
+    "    hasRef() { return this._reffed; }\n"
     "    refresh() {\n"
-    "      host.clearTimer(this._id);\n"
-    "      this._id = host.setTimer(this._fn, this._delay, this._repeat);\n"
+    "      if (this._closed) return this;\n"
+    "      if (this._destroyed) this._arm();\n"
+    "      else host.refreshTimer(this._id);\n"
     "      return this;\n"
     "    }\n"
-    "    close() { host.clearTimer(this._id); return this; }\n"
+    "    close() { this._closed = true; this._destroyed = true; timers.delete(this._id); host.clearTimer(this._id, false); return this; }\n"
+    "    [Symbol.dispose]() { this.close(); }\n"
     "    [Symbol.toPrimitive]() { return this._id; }\n"
     "  }\n"
     "  const mkTimer = (fn, ms, args, repeat) => {\n"
     "    if (typeof fn !== 'function') {\n"
     "      throw new TypeError('The \"callback\" argument must be of type function. Received type ' + typeof fn);\n"
     "    }\n"
-    "    const cb = args.length === 0 ? fn : () => fn(...args);\n"
-    "    return new Timeout(cb, Number(ms), repeat);\n"
+    "    return new Timeout(fn, Number(ms), args, repeat);\n"
     "  };\n"
     "  g.setTimeout = (fn, ms, ...args) => mkTimer(fn, ms, args, false);\n"
     "  g.setInterval = (fn, ms, ...args) => mkTimer(fn, ms, args, true);\n"
     "  g.clearTimeout = (t) => {\n"
     "    if (t === undefined || t === null) return;\n"
     "    const id = typeof t === 'number' ? t : Number(t);\n"
-    "    if (Number.isFinite(id)) host.clearTimer(id);\n"
+    "    if (Number.isFinite(id)) {\n"
+    "      const timer = timers.get(id);\n"
+    "      if (timer) timer.close(); else host.clearTimer(id, false);\n"
+    "    }\n"
     "  };\n"
     "  g.clearInterval = g.clearTimeout;\n"
+    "  class Immediate {\n"
+    "    constructor(fn, args) {\n"
+    "      this._reffed = true; this._destroyed = false;\n"
+    "      this._id = host.setTimer(() => {\n"
+    "        this._destroyed = true; this._reffed = false; fn.apply(this, args);\n"
+    "      }, 0, false, true);\n"
+    "    }\n"
+    "    ref() { if (!this._destroyed) { this._reffed = true; host.refTimer(this._id, true, true); } return this; }\n"
+    "    unref() { if (!this._destroyed) { this._reffed = false; host.refTimer(this._id, false, true); } return this; }\n"
+    "    hasRef() { return this._reffed; }\n"
+    "    _close() { this._destroyed = true; this._reffed = false; host.clearTimer(this._id, true); }\n"
+    "    [Symbol.dispose]() { this._close(); }\n"
+    "  }\n"
+    "  g.setImmediate = (fn, ...args) => {\n"
+    "    if (typeof fn !== 'function') throw new TypeError('The \"callback\" argument must be of type function. Received type ' + typeof fn);\n"
+    "    return new Immediate(fn, args);\n"
+    "  };\n"
+    "  g.clearImmediate = (immediate) => { if (immediate instanceof Immediate) immediate._close(); };\n"
     "\n"
     "  class ReadableStream {\n"
     "    constructor(source, _strategy) {\n"
@@ -1673,7 +1707,6 @@ static void web_timer_fire_cb(ScrClosure *env) {
 static JSValue web_host_set_timer(JSContext *ctx, JSValueConst this_val,
                                   int argc, JSValueConst *argv) {
   (void)this_val;
-  (void)argc;
   double ms = 0;
   if (JS_ToFloat64(ctx, &ms, argv[1])) return JS_EXCEPTION;
   bool repeat = JS_ToBool(ctx, argv[2]) > 0;
@@ -1689,17 +1722,45 @@ static JSValue web_host_set_timer(JSContext *ctx, JSValueConst this_val,
   scr_box_set_ref(box, h); /* the box owns the +1 */
   ScrClosure *cb = scr_closure_new((void *)web_timer_fire_cb, 1);
   cb->caps[0] = box;
-  double id = repeat ? scr_set_interval(cb, ms) : scr_set_timeout_handle(cb, ms);
+  bool immediate = argc > 3 && JS_ToBool(ctx, argv[3]) > 0;
+  double id = immediate ? scr_set_immediate(cb)
+                        : repeat ? scr_set_interval(cb, ms) : scr_set_timeout_handle(cb, ms);
   return JS_NewFloat64(ctx, id);
 }
 
 static JSValue web_host_clear_timer(JSContext *ctx, JSValueConst this_val,
                                     int argc, JSValueConst *argv) {
   (void)this_val;
+  double id = 0;
+  if (JS_ToFloat64(ctx, &id, argv[0])) return JS_EXCEPTION;
+  if (argc > 1 && JS_ToBool(ctx, argv[1]) > 0) scr_clear_immediate(id);
+  else scr_clear_interval(id);
+  return JS_UNDEFINED;
+}
+
+static JSValue web_host_ref_timer(JSContext *ctx, JSValueConst this_val,
+                                int argc, JSValueConst *argv) {
+  (void)this_val;
   (void)argc;
   double id = 0;
   if (JS_ToFloat64(ctx, &id, argv[0])) return JS_EXCEPTION;
-  scr_clear_interval(id);
+  bool reffed = JS_ToBool(ctx, argv[1]) > 0;
+  bool immediate = JS_ToBool(ctx, argv[2]) > 0;
+  if (immediate) {
+    if (reffed) scr_immediate_ref(id); else scr_immediate_unref(id);
+  } else {
+    if (reffed) scr_timer_ref(id); else scr_timer_unref(id);
+  }
+  return JS_UNDEFINED;
+}
+
+static JSValue web_host_refresh_timer(JSContext *ctx, JSValueConst this_val,
+                                    int argc, JSValueConst *argv) {
+  (void)this_val;
+  (void)argc;
+  double id = 0;
+  if (JS_ToFloat64(ctx, &id, argv[0])) return JS_EXCEPTION;
+  scr_timer_refresh(id);
   return JS_UNDEFINED;
 }
 
@@ -1877,8 +1938,10 @@ void scr_island_web_boot(void *jsctx) {
   JS_SetPropertyStr(ctx, host, "write", JS_NewCFunction(ctx, web_host_write, "write", 2));
   JS_SetPropertyStr(ctx, host, "tzname", JS_NewCFunction(ctx, web_host_tzname, "tzname", 1));
   JS_SetPropertyStr(ctx, host, "timer", JS_NewCFunction(ctx, web_host_timer, "timer", 2));
-  JS_SetPropertyStr(ctx, host, "setTimer", JS_NewCFunction(ctx, web_host_set_timer, "setTimer", 3));
-  JS_SetPropertyStr(ctx, host, "clearTimer", JS_NewCFunction(ctx, web_host_clear_timer, "clearTimer", 1));
+  JS_SetPropertyStr(ctx, host, "setTimer", JS_NewCFunction(ctx, web_host_set_timer, "setTimer", 4));
+  JS_SetPropertyStr(ctx, host, "clearTimer", JS_NewCFunction(ctx, web_host_clear_timer, "clearTimer", 2));
+  JS_SetPropertyStr(ctx, host, "refTimer", JS_NewCFunction(ctx, web_host_ref_timer, "refTimer", 3));
+  JS_SetPropertyStr(ctx, host, "refreshTimer", JS_NewCFunction(ctx, web_host_refresh_timer, "refreshTimer", 1));
   JSValue r = JS_Call(ctx, fn, JS_UNDEFINED, 1, (JSValueConst *)&host);
   JS_FreeValue(ctx, host);
   JS_FreeValue(ctx, fn);
diff --git a/tests/fixtures/npm/cases/node24-promise-timers/main.ts b/tests/fixtures/npm/cases/node24-promise-timers/main.ts
new file mode 100644
index 000000000..1fae75104
--- /dev/null
+++ b/tests/fixtures/npm/cases/node24-promise-timers/main.ts
@@ -0,0 +1,4 @@
+// @dynamic
+// @stderr
+import { report } from "node24-promise-timers-fixture";
+await report();
diff --git a/tests/fixtures/npm/cases/node24-promise-timers/package.json b/tests/fixtures/npm/cases/node24-promise-timers/package.json
new file mode 100644
index 000000000..089153bcb
--- /dev/null
+++ b/tests/fixtures/npm/cases/node24-promise-timers/package.json
@@ -0,0 +1 @@
+{"type":"module"}
diff --git a/tests/fixtures/npm/cases/node24-timers-unref/main.ts b/tests/fixtures/npm/cases/node24-timers-unref/main.ts
new file mode 100644
index 000000000..23159b40c
--- /dev/null
+++ b/tests/fixtures/npm/cases/node24-timers-unref/main.ts
@@ -0,0 +1,4 @@
+// @dynamic
+// @stderr
+import { unref } from "node24-promise-timers-fixture";
+unref();
diff --git a/tests/fixtures/npm/cases/node24-timers-unref/package.json b/tests/fixtures/npm/cases/node24-timers-unref/package.json
new file mode 100644
index 000000000..089153bcb
--- /dev/null
+++ b/tests/fixtures/npm/cases/node24-timers-unref/package.json
@@ -0,0 +1 @@
+{"type":"module"}
diff --git a/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.d.ts b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.d.ts
new file mode 100644
index 000000000..de5fbac50
--- /dev/null
+++ b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.d.ts
@@ -0,0 +1,2 @@
+export function report(): Promise<void>;
+export function unref(): void;
diff --git a/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.js b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.js
new file mode 100644
index 000000000..647bb68b6
--- /dev/null
+++ b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/index.js
@@ -0,0 +1,165 @@
+import { setTimeout as delay, setImmediate as immediate, setInterval as interval, scheduler } from 'node:timers/promises';
+import timers from 'node:timers';
+
+export async function report() {
+  const line = (name, value) => console.log(name, JSON.stringify(value));
+  const shape = e => [e.name, e.code, e.message];
+  const reject = async (name, fn) => { try { await fn(); line(name, 'no error'); } catch (e) { line(name, shape(e)); } };
+  for (const value of [null, false, '5', {}, [], 1n, Symbol('delay')]) {
+    await reject('timeout delay', () => delay(value));
+    const iterator = interval(value);
+    line('interval lazy validation', typeof iterator.next);
+    await reject('interval delay', () => iterator.next());
+    await reject('scheduler delay', () => scheduler.wait(value));
+  }
+  for (const value of [null, false, 3, 'bad', [], () => {}]) {
+    await reject('timeout options', () => delay(1, undefined, value));
+    await reject('immediate options', () => immediate(undefined, value));
+    await reject('interval options', () => interval(1, undefined, value).next());
+  }
+  for (const key of ['signal', 'ref']) {
+    for (const value of [null, 0, 'bad', {}]) {
+      const options = { [key]: value };
+      await reject('timeout ' + key, () => delay(1, undefined, options));
+      await reject('immediate ' + key, () => immediate(undefined, options));
+      await reject('interval ' + key, () => interval(1, undefined, options).next());
+    }
+  }
+  {
+    let threw = false, promise;
+    try { promise = delay('bad'); } catch { threw = true; }
+    line('invalid returns rejection', [threw, promise instanceof Promise]);
+    await promise.catch(() => {});
+    line('default values', [await delay(), await immediate(), await scheduler.wait(0), await scheduler.yield()]);
+    const value = { answer: 42 };
+    line('timeout value identity', await delay(1.5, value) === value);
+    line('immediate value identity', await immediate(value) === value);
+  }
+  for (const kind of ['timeout', 'immediate', 'scheduler']) {
+    for (const preaborted of [false, true]) {
+      const ac = new AbortController(), cause = { why: 'cancelled' };
+      ac.signal.addEventListener('abort', e => e.stopImmediatePropagation());
+      if (preaborted) ac.abort(cause);
+      const promise = kind === 'timeout' ? delay(60000, 'unused', { signal: ac.signal })
+        : kind === 'immediate' ? immediate('unused', { signal: ac.signal })
+        : scheduler.wait(60000, { signal: ac.signal });
+      if (!preaborted) ac.abort(cause);
+      try { await promise; } catch (e) { line('cancelled ' + kind, [preaborted, ...shape(e), e.cause === cause]); }
+    }
+  }
+  {
+    const ac = new AbortController(); ac.abort();
+    try { await delay(60000, undefined, { signal: ac.signal }); }
+    catch (e) { line('default abort cause', [shape(e), e.cause === ac.signal.reason, e.cause.name]); }
+  }
+  {
+    const ac = new AbortController(); let removed = 0;
+    const original = ac.signal.removeEventListener.bind(ac.signal);
+    ac.signal.removeEventListener = (...args) => { removed++; return original(...args); };
+    await delay(1, undefined, { signal: ac.signal });
+    await immediate(undefined, { signal: ac.signal });
+    await scheduler.wait(1, { signal: ac.signal });
+    const iterator = interval(1, undefined, { signal: ac.signal }); await iterator.next(); await iterator.return();
+    line('completed signal cleanup', removed); ac.abort('after completion');
+  }
+  {
+    const ac = new AbortController(); let removed = 0;
+    const original = ac.signal.removeEventListener.bind(ac.signal);
+    ac.signal.removeEventListener = (...args) => { removed++; return original(...args); };
+    const promise = delay(60000, undefined, { signal: ac.signal }); ac.abort('early');
+    await promise.catch(() => {}); line('cancelled signal cleanup', removed);
+  }
+  {
+    const value = { tick: 'value' }, iterator = interval(1, value);
+    line('interval self', iterator[Symbol.asyncIterator]() === iterator);
+    line('interval identity', (await iterator.next()).value === value);
+    line('interval return', await iterator.return('finished'));
+    line('interval done', await iterator.next());
+    let ticks = 0; for await (const value of interval(1, 'tick')) { if (value === 'tick') ticks++; if (ticks === 3) break; }
+    line('interval loop break', ticks);
+  }
+  for (const preaborted of [false, true]) {
+    const ac = new AbortController(), cause = { why: 'interval cancellation' };
+    ac.signal.addEventListener('abort', e => e.stopImmediatePropagation());
+    if (preaborted) ac.abort(cause);
+    const iterator = interval(60000, 'unused', { signal: ac.signal });
+    const a = iterator.next().catch(e => [shape(e), e.cause === cause]), b = iterator.next();
+    if (!preaborted) ac.abort(cause);
+    line('interval cancelled', [preaborted, await a, await b, await iterator.next()]);
+  }
+  {
+    const ac = new AbortController(), iterator = interval(5, 'buffered', { signal: ac.signal });
+    await iterator.next(); await delay(100); ac.abort('buffered abort');
+    line('interval drains buffered tick', await iterator.next()); await iterator.return();
+  }
+  {
+    const iterator = interval(1, 'value'), failure = new Error('thrown');
+    await iterator.next(); try { await iterator.throw(failure); } catch (e) { line('interval throw identity', e === failure); }
+    line('interval throw done', await iterator.next());
+    const lazy = interval('invalid delay'); line('return before start', await lazy.return('skipped'));
+  }
+  {
+    const keep = setTimeout(() => {}, 60000);
+    line('unref timeout with live loop', await delay(1, 'value', { ref: false }));
+    line('unref immediate with live loop', await immediate('value', { ref: false }));
+    const iterator = interval(1, 'value', { ref: false }); line('unref interval with live loop', await iterator.next()); await iterator.return();
+    await scheduler.wait(1, { ref: false }); line('unref scheduler with live loop', true); clearTimeout(keep);
+  }
+  {
+    const log = [];
+    await new Promise(resolve => setImmediate(() => {
+      setImmediate(() => log.push('first'));
+      queueMicrotask(() => log.push('microtask'));
+      setImmediate(() => { log.push('second'); setImmediate(() => { log.push('nested'); resolve(); }); });
+    }));
+    line('immediate queue', log);
+    line('global module identity', [timers.setImmediate === setImmediate, timers.clearImmediate === clearImmediate]);
+  }
+  {
+    const timer = setTimeout(() => {}, 60000), id = +timer;
+    line('timeout ref control', [timer.hasRef(), timer.unref() === timer, timer.hasRef(), timer.ref() === timer, timer.hasRef()]);
+    timer.unref(); timer.refresh(); line('refresh preserves ref and identity', [timer.hasRef(), +timer === id]);
+    clearTimeout(String(id)); timer.refresh(); line('cleared timeout stays cleared', timer.hasRef());
+    const disposable = setTimeout(() => line('disposed timer ran', true), 60000);
+    line('timeout disposal', disposable[Symbol.dispose]() === undefined);
+    const stopped = setInterval(() => line('disposed interval ran', true), 60000); stopped[Symbol.dispose]();
+    const fired = setTimeout(function(a, b) { line('timeout receiver', [this === fired, a, b]); }, 1, 'a', 'b');
+    await delay(10); line('fired timeout ref', fired.hasRef());
+    const refreshed = new Promise(resolve => {
+      let calls = 0;
+      const handle = setTimeout(() => { if (++calls === 1) handle.refresh(); else { line('refresh after firing', calls); resolve(); } }, 1);
+    }); await refreshed;
+  }
+  {
+    const handle = setImmediate(() => line('cleared immediate ran', true));
+    line('immediate ref control', [handle.hasRef(), handle.unref() === handle, handle.hasRef(), handle.ref() === handle, handle.hasRef()]);
+    clearImmediate(handle); line('cleared immediate ref', handle.hasRef());
+    line('immediate disposal', setImmediate(() => line('disposed immediate ran', true))[Symbol.dispose]() === undefined);
+    await new Promise(resolve => {
+      const fired = setImmediate(function(a, b) { line('immediate receiver', [this === fired, a, b, fired.hasRef()]); resolve(); }, 'a', 'b');
+    });
+  }
+  {
+    line('scheduler prototype', Object.getOwnPropertyNames(Object.getPrototypeOf(scheduler)));
+    await reject('scheduler constructor', () => new scheduler.constructor());
+    await reject('scheduler wait receiver', () => scheduler.wait.call({}, 1));
+    await reject('scheduler yield receiver', () => scheduler.yield.call({}));
+    const ac = new AbortController(); let signals = 0, refs = 0;
+    const options = { get signal() { signals++; return ac.signal; }, get ref() { refs++; return true; } };
+    await delay(1, undefined, options); await immediate(undefined, options);
+    const iterator = interval(1, undefined, options); await iterator.next(); await iterator.return();
+    line('option getters', [signals, refs]);
+  }
+}
+
+export function unref() {
+  const unexpected = () => console.log('unreferenced timer fired');
+  setTimeout(unexpected, 60000).unref();
+  setInterval(unexpected, 60000).unref();
+  setImmediate(unexpected).unref();
+  delay(60000, undefined, { ref: false }).then(unexpected);
+  immediate(undefined, { ref: false }).then(unexpected);
+  interval(60000, undefined, { ref: false }).next().then(unexpected);
+  scheduler.wait(60000, { ref: false }).then(unexpected);
+  console.log('scheduled unreferenced timers');
+}
diff --git a/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/package.json b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/package.json
new file mode 100644
index 000000000..f5d3b201b
--- /dev/null
+++ b/tests/fixtures/npm/node_modules/node24-promise-timers-fixture/package.json
@@ -0,0 +1 @@
+{"name":"node24-promise-timers-fixture","version":"1.0.0","type":"module","main":"index.js","types":"index.d.ts"}
diff --git a/tests/harness/web-globals.test.ts b/tests/harness/web-globals.test.ts
index 47d1fc3f6..425e19a76 100644
--- a/tests/harness/web-globals.test.ts
+++ b/tests/harness/web-globals.test.ts
@@ -119,12 +119,12 @@ describe(`island web globals (scriptc-only${sanitize ? ", sanitized" : ""})`, ()
     // Event and buffer.Blob at LOAD); structuredClone joined with the
     // globals lane (the HTML StructuredSerialize subset, cycles
     // included); WritableStream/FormData/WebSocket stay fenced by
-    // absence. URL, Buffer, and the immediate-timer globals are installed
-    // only when the embedded npm module bootstrap runs.
+    // absence. URL and Buffer are installed only when the embedded npm
+    // module bootstrap runs; immediate timers use the native check queue.
     expect(out).toBe(
       "function function function function function function function function function " +
         "object object function function function function function function " +
-        "undefined function undefined undefined undefined undefined undefined undefined",
+        "undefined function undefined undefined undefined undefined function function",
     );
   });