fix(settings): format about release dates without timezone

crates/agent-gui/src/pages/settings/AboutSection.tsx

@@ -15,20 +15,14 @@ import { Button } from "../../components/ui/button";
 import { useLocale } from "../../i18n";
 import type { AppUpdateCheckResult, AppUpdateController } from "../../lib/appUpdates";
 import { updateUpdateSettings } from "../../lib/settings";
+import { formatReleaseDate } from "./aboutDate";
 import { AgentActivationSwitch } from "./shared";
 import type { SettingsSectionProps } from "./types";
 
 type AboutSectionProps = SettingsSectionProps & {
   appUpdate: AppUpdateController;
 };
 
-function formatReleaseDate(value?: string | null) {
-  if (!value) return "";
-  const date = new Date(value);
-  if (Number.isNaN(date.getTime())) return value;
-  return date.toLocaleString();
-}
-
 function releaseTitle(result?: AppUpdateCheckResult) {
   if (!result) return "";
   return result.releaseName?.trim() || result.releaseTag?.trim() || result.version || "";

crates/agent-gui/src/pages/settings/aboutDate.ts

@@ -0,0 +1,58 @@
+const PORTABLE_RELEASE_DATE_PATTERN =
+  /^(\d{4})-(\d{1,2})-(\d{1,2})[ T](\d{1,2}):(\d{2})(?::(\d{2})(\.\d+)?)?(?:\s*(Z|[+-]\d{2}:\d{2})(?::\d{2})?)?$/i;
+
+function padDatePart(value: number | string) {
+  return String(value).padStart(2, "0");
+}
+
+function parsePortableReleaseDate(value: string) {
+  const match = value.match(PORTABLE_RELEASE_DATE_PATTERN);
+  if (!match) return null;
+
+  const [, yearText, monthText, dayText, hourText, minuteText, secondText, fraction = "", zone] =
+    match;
+  const year = Number.parseInt(yearText, 10);
+  const month = Number.parseInt(monthText, 10);
+  const day = Number.parseInt(dayText, 10);
+  const hour = Number.parseInt(hourText, 10);
+  const minute = Number.parseInt(minuteText, 10);
+  const second = secondText ? Number.parseInt(secondText, 10) : 0;
+
+  if (zone) {
+    const normalized = `${yearText}-${padDatePart(month)}-${padDatePart(day)}T${padDatePart(
+      hour,
+    )}:${padDatePart(minute)}:${padDatePart(second)}${fraction}${zone.toUpperCase()}`;
+    const date = new Date(normalized);
+    return Number.isNaN(date.getTime()) ? null : date;
+  }
+
+  const date = new Date(year, month - 1, day, hour, minute, second);
+  if (
+    date.getFullYear() !== year ||
+    date.getMonth() !== month - 1 ||
+    date.getDate() !== day ||
+    date.getHours() !== hour ||
+    date.getMinutes() !== minute
+  ) {
+    return null;
+  }
+  return date;
+}
+
+function formatDateTime(date: Date) {
+  return `${date.getFullYear()}-${padDatePart(date.getMonth() + 1)}-${padDatePart(
+    date.getDate(),
+  )} ${padDatePart(date.getHours())}:${padDatePart(date.getMinutes())}`;
+}
+
+export function formatReleaseDate(value?: string | null) {
+  const trimmed = value?.trim();
+  if (!trimmed) return "";
+
+  const portableDate = parsePortableReleaseDate(trimmed);
+  if (portableDate) return formatDateTime(portableDate);
+
+  const date = new Date(trimmed);
+  if (Number.isNaN(date.getTime())) return trimmed;
+  return formatDateTime(date);
+}

crates/agent-gui/test/settings/about-date.test.mjs

@@ -0,0 +1,18 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { createTsModuleLoader } from "../helpers/load-ts-module.mjs";
+
+process.env.TZ = "UTC";
+
+const loader = createTsModuleLoader();
+const { formatReleaseDate } = loader.loadModule("src/pages/settings/aboutDate.ts");
+
+test("formats updater release dates without seconds, milliseconds, or timezone", () => {
+  assert.equal(formatReleaseDate("2026-06-21 9:26:56.441 +00:00:00"), "2026-06-21 09:26");
+  assert.equal(formatReleaseDate("2026-06-21T09:26:56.441Z"), "2026-06-21 09:26");
+});
+
+test("keeps unknown release date values readable", () => {
+  assert.equal(formatReleaseDate("  not-a-date  "), "not-a-date");
+  assert.equal(formatReleaseDate(null), "");
+});