How Long Until — Time Highlighter

See how long until a time on any page. Automatic time zone highlighting, local time conversion and a live countdown.

How long until 18:00 UTC? Read the answer right where you found the time. How Long Until automatically underlines supported times on the web. Hover over one to see a live countdown, its date and time in your own time zone, and the original time zone. Keep reading the page without copying times into a converter. WHAT IT DOES • Automatically highlights supported dates and times after you enable website access. • Converts UTC, GMT, explicit offsets and common time zone abbreviations to your local time. • Shows how long until a future event, or how long ago a dated event happened. • Explains the date used when a time has no date: the next occurrence of that time. • Lets you choose a target time zone, use a 12- or 24-hour clock, and change abbreviation defaults. • Includes global and per-site controls. EVERYTHING RUNS LOCALLY All executable code and resources are included in the extension. No remote scripts, analytics, advertising, account or page-text transmission. The source code and build instructions are public. EXAMPLES Check how long until 3 PM EST, translate 18:00 UTC to local time, or understand an ISO timestamp in an announcement. Times without a zone and unsupported date formats are left alone. Browser-internal pages, editable fields and code samples are excluded. TIME ZONE ASSUMPTIONS EST and PST are literal fixed offsets; ET and PT follow daylight saving. CST defaults to US Central Standard Time and IST to India. You can change abbreviation defaults in settings. FREE CORE, FUTURE REMINDERS Highlighting, local time conversion and the countdown are free. Reminders are a planned paid feature, marked “Pro — Soon”. This version does not include reminders, billing or notification permissions.