Date calculator

How it works

Years and months move the calendar month first. When the day does not exist in the new month the last day of that month is used, so 31 January plus one month is the last day of February. Weeks and days then move the date. Hours, minutes and seconds are added as elapsed time, so across a daylight saving change the clock time can move by an extra hour while the elapsed time stays exact.

Leave the time empty to work with dates only. To count working days instead, use the business days calculator; to find the gap between two dates, use the date difference calculator.