Date & Time
Date math, timestamps, and time-zone conversions.
The date and time category collects the tools for the small calculations that come up around scheduling, age and duration math, and time zones — plus practical timers for everyday use. Date arithmetic, Unix timestamp conversion, exact age calculation, countdown timers, time-zone conversion across regions, a precise stopwatch with lap times, and a configurable focus timer based on the Pomodoro technique.
All of them run in your browser, drawing on the browser's built-in IANA time-zone database for daylight-saving and offset rules. The timers are timestamp-based rather than ticking counters, so they stay accurate even when the browser throttles the tab in the background — switch away for ten minutes, come back, and the remaining time is what it should be rather than ten minutes behind. Birth dates, deadlines, and schedules are personal data; none of it is uploaded or logged.