diff --git a/CHANGELOG.md b/CHANGELOG.md
index d9a6894..e506bc8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,31 @@
+## 0.5.0
+
+- Adopt OKF revision `62432a0`: every timestamp is an ISO 8601 datetime with a
+  UTC offset. A date-only or offset-less value raises the non-blocking
+  `okf/timestamp-without-offset` advisory naming the exact field, and
+  `OkfSpecValidation.isConformant` is unchanged, so a bundle that validates today
+  still validates. `okf validate --strict` is the exception: it escalates
+  advisories to failures, so it starts failing on date-only timestamps it used to
+  accept. Run `okf format --migrate-timestamps` on those bundles, or drop
+  `--strict` until you have.
+- Compare staleness as an instant rather than a local calendar day. `stale_after`
+  was read as a calendar date and compared in the caller's local zone; it is now
+  an instant, stale when `now >= stale_after`. East of UTC a concept goes stale
+  later than before — two hours in Berlin, twelve in Auckland — and west of UTC it
+  can now become stale on the previous local day. Callers in UTC see no change.
+- Add `okf format --migrate-timestamps`, which rewrites date-only values to
+  `T00:00:00Z` and reports every change. It is opt-in, idempotent, writes nothing
+  under `--check`, and leaves offset-less datetimes alone rather than guessing a
+  zone for them. Migrating a date-only `verified.at` can raise a concept's
+  `trust_tier` from `unverified` to `human-reviewed`, because the verification now
+  carries a usable time; that change is visible in `okf graph`.
+- Reject impossible timestamps through one strict parser. `2026-02-30` previously
+  rolled over into March 2 and was accepted; it is now rejected everywhere. Date
+  values still read as midnight UTC for `stale_after`, `usage_window` and
+  `last_modified`, where a date has always been valid. `generated.at` and
+  `verified[].at` have always required a time, so a date-only value there carries
+  no instant and does not count as a verification.
+
 ## 0.4.2
 
 - No changes to the package. This release completes the deployment pipeline:
diff --git a/README.md b/README.md
index a896ef3..bf3118e 100644
--- a/README.md
+++ b/README.md
@@ -94,7 +94,7 @@ Gate a repository on OKF Spec conformance with one step and no configuration:
 
 ```yaml
 steps:
-  - uses: conceptadev/okf@v0.4.2
+  - uses: conceptadev/okf@v0.5.0
 ```
 
 The action downloads the released `okf` archive for the ref in `uses`, unpacks
diff --git a/lib/src/version.dart b/lib/src/version.dart
index 390de2b..718b8f9 100644
--- a/lib/src/version.dart
+++ b/lib/src/version.dart
@@ -1,2 +1,2 @@
 /// The package version reported by `okf --version` and the MCP server.
-const okfPackageVersion = '0.4.2';
+const okfPackageVersion = '0.5.0';
diff --git a/pubspec.yaml b/pubspec.yaml
index 9873637..007e781 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,6 +1,6 @@
 name: okf
 description: A format-first Dart toolkit for reading, validating, writing, indexing, and graphing Open Knowledge Format bundles.
-version: 0.4.2
+version: 0.5.0
 repository: https://github.com/conceptadev/okf
 issue_tracker: https://github.com/conceptadev/okf/issues
 topics: