Time & Date tools
Time & Date calculators
Ages, durations, time zones, countdowns — anything you measure in time, calculated cleanly.
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PopularAge Calculator
How old are you — to the day.
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Date Calculator
Add or subtract days from a date.
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Date Difference Calculator
Days, weeks, months between two dates.
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Time Duration Calculator
Time elapsed between two clock times.
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Hours Calculator
Total hours and minutes between times.
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Countdown Timer
Count down to any moment.
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Stopwatch
Lap-friendly precision stopwatch.
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Timestamp Converter
Unix timestamps ↔ human dates.
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Time Zone Converter
Convert times across cities.
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Business Days Calculator
Count working days between dates.
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Week Number Calculator
ISO week number for any date.
Most used in Time & Date
Common tasks
- Find someone's age to the day
- Count days, weeks or months between two dates
- Add or subtract days, weeks or months
- Count working days, skipping weekends
- Convert times across cities or to UTC
All Time & Date calculators
- Age Calculatorhow old am I if born in 1995
- Date Calculator90 days from today
- Date Difference Calculatordays between Jan 1 and today
- Time Duration Calculatorfrom 9:15 to 17:45
- Hours Calculatorhow many hours from 9 to 5
- Countdown Timercountdown to new year
- Stopwatchstopwatch online
- Timestamp Converter1700000000 to date
- Time Zone Converter3pm EST in PST
- Business Days Calculator10 business days from today
- Week Number Calculatorwhat iso week is it
Frequently asked
Do these handle time zones correctly?
Time Zone Converter uses your browser's timezone database, including DST. Date math runs in your local time.
What's the difference between Hours and Time Duration?
Hours Calculator totals decimal hours across multiple times; Time Duration handles a single from→to span, including overnight.
Are weekends excluded automatically?
Only in Business Days Calculator. Date Difference counts every calendar day.
How are leap years handled?
All date math uses the standard Gregorian calendar, so Feb 29 is included in leap years and ages roll on March 1 in non-leap years.