Features
Time format setting (12-hour / 24-hour) — a new toggle on the Settings page (settings.timeFormat, default 24-hour) controls how every time on the Timezone tab is shown. Because native date/time pickers always render in the OS locale and can't be forced to a format, the reference picker uses a custom, format-aware time entry (hour/minute fields plus an AM/PM toggle in 12-hour mode) — so the picker and the displayed rows always match.
Bug Fixes
Reference time was read in the wrong timezone. It used the machine's local timezone instead of the home timezone, so a 10:00 reference with a Melbourne home wrongly showed 14:30. The reference wall clock is now interpreted in the home timezone and converted to each zone from there. Conversion uses a two-pass Intl.DateTimeFormat offset lookup, so it is correct across DST boundaries.
Reference captured only a time, never a date. The control now captures date and time; setting just one half auto-fills the other from the current home-timezone clock.
Reference picker and rows disagreed on format. The rows displayed 24-hour while the native picker showed AM/PM (from the OS locale). Both now follow the single Time Format setting.

Open in a separate window — a new app-bar button (mdi-open-in-new, beside the theme toggle) pops the popup out into its own chrome-less, resizable app window via chrome.windows.create({ type: 'popup' }), reusing popup.html?view=window so all four tools (Codec, Format, Clipboard, Timezone) plus Settings are available. Clicking again focuses the existing window instead of opening duplicates — the window id is tracked in chrome.storage.session, and a stale id (window since closed) is caught and replaced. No new manifest permissions were added: the windows API needs none, and focus-existing avoids the tabs permission.

Version on the Settings page — an about-stamp footer echoes the OMNIUTILS wordmark and tags it with the running version (e.g. v1.2). The version is read from chrome.runtime.getManifest().version, so it always tracks manifest.json and is never hardcoded.