Time tools
Timestamps, time zones and durations, computed entirely in your browser.
- Timestamp converter
Unix to ISO 8601 and back, with relative time.
- Timezone converter
One moment across every zone, laid out side by side.
- Duration converter
Milliseconds up to weeks, with a human breakdown.
- Availability sharer
Share free slots by link. No calendar connection.
- Date math
Add durations to a date and diff two dates, wall-clock vs elapsed across DST, both stated.
- Calendar converter
Gregorian ⇄ Hijri, Hebrew, Persian, Chinese, and eleven more, from your browser's ICU tables.
- ISO 8601 Duration
Parse and build ISO 8601 durations: exact elapsed totals for time units, honest refusal to invent one for months.
- ISO Week Number
Date to ISO week date and back: week 1 holds the first Thursday, weeks start Monday.
- Business Day Calculator
Count or add business days with your own holiday list and weekend definition. No holiday API exists here.
- Stopwatch and Countdown
A stopwatch with laps and a countdown: wall-clock math that survives background throttling, memory-only.
- Epoch Batch Converter
Many Unix timestamps at once (ISO, UTC, RFC 2822, relative), with row and byte caps.
11 tools · your files are processed on your device. The few tools that talk to the internet say so before they do.