Append your local time after unambiguous absolute times on any page (e.g. "14:42 UTC" -> " (10:42 AM EDT)"), non-destructively.
Appends your local time after any unambiguous absolute time on a web page — non-destructively, inline, on any site.
14:42 UTC -> 14:42 UTC (10:42 AM EDT)
19:00Z -> 19:00Z (3:00 PM EDT)
May 29, 08:45 UTC -> May 29, 08:45 UTC (4:45 AM EDT)
The original text is never changed — a small, dimmed (…) is added right after it. No configuration: your timezone is detected automatically.
<time datetime="…"> elements (most reliable).Z / UTC / GMT (optionally with a numeric offset like UTC+8, GMT+5:30) or a bare numeric offset (±HH:MM / ±HHMM). Examples: 14:42 UTC, 19:00Z, 2:42 PM GMT, 09:30 UTC+8, 15:00 -05:00.May 29, 08:45 UTC, where the time and UTC live in separate elements.The source offset is parsed, the absolute instant is computed, and that instant is formatted in your local zone via Intl.DateTimeFormat. Daylight saving is resolved per-instant by the browser — never hand-computed — so spring/fall transitions are correct. If a time is already in your local zone, nothing is added.
*://*/*), static and dynamically loaded content (a scoped MutationObserver catches late-rendered times).10:42 AM EDT).EDT, CST, …) are not matched — CST alone is ambiguous (China / US-Central / Cuba).2 hours ago) and bare ISO strings embedded in prose are skipped.<input> / <textarea> / <code> / <pre> / contenteditable are left alone.A cheap pre-test gates the page scan, formatters are cached, and DOM writes are isolated from the observer, so re-matchable output (like GMT+8) never re-annotates itself and there is no CPU spin.
Open an issue. Full docs and test cases: GitHub README; changelog: CHANGELOG.