Time & date

Ages, deadlines, time zones and timers — calendar arithmetic done properly.

• Date Calculator10·01Count days between two dates, add or subtract time, and work out exact age in years, months and days.
• Time Zone Converter10·02Convert times between cities with the browser's IANA time-zone database — DST applied automatically, day changes flagged, every world clock in one table.
• Timer & Stopwatch10·03A countdown timer that understands 5m, 1:30 or 90 — with a clear alarm — and a stopwatch with laps. Keeps counting in a background tab.
• Age Calculator10·04Exact age in years, months and days — calendar-aware, leap-day honest — with total days lived, the weekday you were born, and the countdown to your next birthday.
• Working Days Calculator10·05Business days between two dates — or the date N working days out — with your own holiday list and weekend pattern, because calendars differ by country.