Date Calculator

Free date calculator to add or subtract whole days, months, or years from a starting date and see the resulting calendar date.

Move through the calendar without tripping over month lengths or leap years.

Your inputs stay on your device

Move a date

live result

Starting date

Operation

Amount

Unit

Month and year changes preserve the day where possible, otherwise they use the last valid day of the resulting month.

Context & Reference

Calculators are most useful when their assumptions are clear. Review these details to better understand the logic behind the results.

Choose an operation and calendar unit, then the calculator moves the starting date by that whole-number amount.

Enter a starting date, choose add or subtract, enter a whole number, and select the calendar unit.

The result includes the new date, weekday, original date, operation, and amount used.

Adding one month to January 31 uses February 28 in a non-leap year because that is the last valid day of the month.

Month and year changes clamp month-end dates rather than overflowing into the following month.

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