Date and Time Calculators
Find an exact age, count the days between two dates, add or subtract time from a date, measure the time between two clock times or count down to an event. The results are exact, including leap years and the different lengths of months.
Each page explains how it counts, for example whether the last day is included, so the number you get is the number you meant to ask for.
All 6 dates and time calculators
- Age CalculatorExact age in years, months and days from a date of birth
- Days Between DatesCount the days between two dates, with weekdays and weekends
- Date Difference CalculatorThe time between two dates in years, months, weeks and days
- Date Addition CalculatorAdd or subtract years, months, weeks, days or business days from a date
- Time Duration CalculatorThe time between two clock times, with overnight spans and unpaid breaks
- Countdown CalculatorA live countdown in days, hours, minutes and seconds to any date
How dates are counted
All calculations use the Gregorian calendar and work on calendar dates, from the year 1 to the year 9999. They do not depend on your time zone or on daylight-saving changes, so the same dates always give the same answer.
Adding a month to the 31st of a month gives the last day of a shorter month, and a birthday on 29 February is handled by the rule stated on the age calculator. Business days skip weekends but not public holidays, which differ between countries.