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Date add / subtract

Move a date by years, months, weeks and days with clear month-end adjustments.

Shifted date
Starting date31January 2024Wed
Result29February 2024Thu
2024-02-29
Calendar-day change29
Month-end adjustmentClamped to month end
January 2024
MonTueWedThuFriSatSun
Pick a day. Arrow keys move by a day or a week.

The calendar edits the starting date.

YYYY-MM-DD
Processed on your device

How it works & useful details

How it works & limits

Years and months are combined into one month shift. If the original day does not exist in that target month, it becomes the target month’s final day. Weeks and days are applied after that adjustment.

For example, January 31 + one month in 2024 is February 29. Adding two months at once gives March 31; adding one month twice can give March 29. Calendar arithmetic supports years 0001–9999 and rejects results outside that range.

Your working space

Explore the live preview, then save a copyable text report. Inputs stay on this device and are cleared by refreshing. Dates use the Gregorian calendar, including before its historical introduction.