diff --git a/docs/agent-environments.md b/docs/agent-environments.md
index a5350caaed..8d1f4c7554 100644
--- a/docs/agent-environments.md
+++ b/docs/agent-environments.md
@@ -755,8 +755,10 @@ recording replayed in its place and never from a recording whose body the probe
 two collections can reuse a live id, and an equal pair stays in that collection. A live id in a later request's path, query or body is translated before the
 environment answers, a path parameter by the collection the live path names (a nested collection keeps its parent values, each decoded once, and a literal route segment stays), except a query value that pages a list, such as `limit`
 or `page`. Each call is checked against the served tool's input schema first, as the MCP server checks it. After mapping, two clock values compare by format only (ISO-8601 strings, and epoch numbers under
-time-named fields), and two different values each side generated on its own compare equal: both UUIDs, or one length of
+`at`, `time`, `date`, `timestamp`, `created`, `updated` or `modified` field names, including snake-case and camel-case forms), and two different values each side generated on its own compare equal: both UUIDs, or one length of
 eight or more with the same character classes and a digit. The report counts each kind of normalised value.
+ISO clock offsets are accepted only within RFC 3339's `00`–`23` hour and `00`–`59` minute ranges.
+Timestamp ordering retains submillisecond precision when the source records it.
 
 Comparison keeps response representations distinct: JSON values compare structurally, text compares as text, and a
 retained base64 body compares by bytes (including with UTF-8 text carrying those same bytes), never by its base64
diff --git a/src/application/environment/environmentCompareDiff.test.ts b/src/application/environment/environmentCompareDiff.test.ts
index 74d3365c37..315a0d4c90 100644
--- a/src/application/environment/environmentCompareDiff.test.ts
+++ b/src/application/environment/environmentCompareDiff.test.ts
@@ -166,6 +166,21 @@ describe("compareAnswers", () => {
   });
 });
 
+describe("clock field names", () => {
+  it("keeps numeric format identifiers literal and recognizes clock field forms", () => {
+    expect(
+      compare({ format: 1196444237 }, { format: 1448695129 }).differences,
+    ).toMatchObject([{ category: "value", pointer: "/format" }]);
+    expect(
+      compare({ updated_at: 1760000000 }, { updated_at: 1760000999 })
+        .differences,
+    ).toEqual([]);
+    expect(
+      compare({ createdAt: 1760000000 }, { createdAt: 1760000999 }).differences,
+    ).toEqual([]);
+  });
+});
+
 describe("comparison body coverage", () => {
   it("compares a live body over the replay limit by status only and counts it", () => {
     const result = compareAnswers(
diff --git a/src/application/environment/environmentCompareDiff.ts b/src/application/environment/environmentCompareDiff.ts
index 32cc0e2684..350363d842 100644
--- a/src/application/environment/environmentCompareDiff.ts
+++ b/src/application/environment/environmentCompareDiff.ts
@@ -52,7 +52,10 @@ export interface Normalised {
 /** At most this many differences are kept per step. */
 export const STEP_DIFFERENCE_LIMIT = 20;
 const VALUE_CHARS = 120;
-const TIME_FIELD = /(at|time|date|timestamp|created|updated|modified)$/iu;
+const TIME_FIELD =
+  /(?:^|[_-])(?:at|time|date|timestamp|created|updated|modified)$/iu;
+const TIME_FIELD_CAMEL =
+  /(?:At|Time|Date|Timestamp|Created|Updated|Modified)$/u;
 const ID_LIST_FIELD = /^(ids|uuids|guids)$/u;
 
 const isObject = (value: JsonValue | undefined): value is JsonObject =>
@@ -76,7 +79,12 @@ const clockFormat = (
   value: JsonValue,
   key: string | undefined,
 ): string | undefined => {
-  if (typeof value === "number" && key !== undefined && !TIME_FIELD.test(key))
+  if (
+    typeof value === "number" &&
+    key !== undefined &&
+    !TIME_FIELD.test(key) &&
+    !TIME_FIELD_CAMEL.test(key)
+  )
     return undefined;
   const clock = readClock(value);
   return clock === undefined ? undefined : formatKey(clock.format);
diff --git a/src/application/environment/environmentCompareIdsIntegration.test.ts b/src/application/environment/environmentCompareIdsIntegration.test.ts
index 3904787063..521853d51f 100644
--- a/src/application/environment/environmentCompareIdsIntegration.test.ts
+++ b/src/application/environment/environmentCompareIdsIntegration.test.ts
@@ -27,6 +27,42 @@ const compareRows = (
 };
 
 describe("environment comparison identifier semantics", () => {
+  it("compares numeric format identifiers literally while normalizing actual clock fields", () => {
+    const fourcc = (value: string) => Buffer.from(value).readUInt32LE(0);
+    const probe = compareRows(
+      [
+        [
+          "GET",
+          "/api/media",
+          {
+            format: fourcc("MJPG"),
+            size: 1,
+            updated_at: "2026-10-20T10:00:00Z",
+          },
+        ],
+      ],
+      [
+        [
+          "GET",
+          "/api/media",
+          {
+            format: fourcc("YUYV"),
+            size: 1,
+            updated_at: "2026-10-17T18:00:03Z",
+          },
+        ],
+      ],
+    );
+    expect(probe.results[0]?.equal).toBe(false);
+    expect(
+      probe.results[0]?.differences.map((difference) => [
+        difference.category,
+        difference.pointer,
+      ]),
+    ).toEqual([["value", "/format"]]);
+    expect(probe.normalised.clocks).toBe(1);
+  });
+
   it("does not normalize measurements after learning an unrelated numeric ID", () => {
     const probe = compareRows(
       [