Date Calculator

Add or subtract days, weeks, months or years from any date and see exactly where you land.

Direction
Result
Resulting date
As YYYY-MM-DD
Days from the start date
Pick a date, choose add or subtract, and enter how far to move.

Everything is calculated in your browser — the dates you enter never leave your device.

FAQ

What is January 31 plus one month?

February has no 31st, so the result lands on the last day of the month instead — February 28, or 29 in a leap year. That is the convention calendars, banks and spreadsheets follow, and the status line tells you whenever it happens.

In what order are years, months, weeks and days applied?

Years and months move first, then weeks and days are added on top. So January 31 plus one month and one day first lands on the end of February, then steps one day into March. A different order could land on a different day, which is why this one is fixed and predictable.

Does it count business days?

No — the calculator moves in calendar days, so weekends and public holidays are included in the count. The result shows the weekday, so you can immediately see when a deadline lands on a Saturday or Sunday and shift it yourself.

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