Date & time
Date arithmetic, time zones, timers and timestamp conversion.
Date difference Days, weeks, months and years between two dates — with or without weekends. Add or subtract days Add days, weeks, months or years to a date, optionally counting business days only. Age calculator Exact age in years, months and days — plus your age on any other date. Time zone converter Compare a time across cities and find the overlap in everyone’s working day. Countdown timer A big, shareable countdown to any moment — good on a projector. Stopwatch Start, stop, lap — with keyboard control and a readable display. Pomodoro timer 25 on, 5 off, with session counts and a gentle chime. Unix timestamp converter Epoch seconds and milliseconds to human dates, in UTC and local time. Week number & day of year ISO week number, day of year, quarter and days remaining, for any date. Duration calculator Add and subtract hours, minutes and seconds — timesheets, video edits, race splits. Business days calculator Working days between dates, skipping weekends and the holidays you pick. Cron expression builder Build a cron schedule, read one back in English, and see the next run times.