Add or Subtract Days
Find the date a given number of days, weeks, months or years before or after another date.
Runs entirely in your browser.
Add or Subtract Days, Weeks, Months or Years
About Add or Subtract Days
Adding days and weeks is simple counting. Adding months and years is not, because the target month may be shorter than the starting one - so this clamps to the last valid day instead of rolling into the next month. Adding one month to 31 January gives 28 February, not 3 March.
That clamping is what almost everyone means by "a month later", and it is what spreadsheet and database date functions do too.
Other Date Tools
- Date Calculator — difference, arithmetic and age on one page
- Age Calculator — exact age and days to the next birthday
- Date Difference — the span between two dates
- Leap Year Checker — is a year a leap year, and why
- Day of the Week — weekday, day of year and ISO week
- Unix Timestamp — epoch seconds to and from a date
- Time Converter — seconds, minutes, hours, days, weeks
