Add or Subtract Days
Shift a date by N days.
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About Add or Subtract Days
Add or subtract days, weeks, months, or years from any start date and instantly see the resulting date along with the day of the week. Flip to the second mode to count the exact number of days between two dates, with weeks and a years/months/days breakdown included.
This date calculator is completely free with no sign-up, and it runs entirely in your browser. Nothing you type is uploaded or stored anywhere. All the math is done locally using your device's calendar, so results are instant and your dates stay private.
Frequently asked questions
- Is this date calculator free to use?
- Yes, it is 100% free with no account, sign-up, or limits. You can add or subtract dates and count days between dates as many times as you like.
- Is my data uploaded or stored anywhere?
- No. Every calculation happens locally in your browser using JavaScript. The dates you enter are never sent to a server, saved, or shared, so your information stays completely private.
- How do I add or subtract days from a date?
- In the first mode, pick a start date, choose Add or Subtract, type a whole number, and select the unit (days, weeks, months, or years). The resulting date and its weekday appear instantly below.
- How does it handle adding months to the end of a month?
- It clamps to the last valid day of the target month. For example, January 31 plus one month becomes February 28 (or February 29 in a leap year) rather than spilling into March.
- Does the calculation get affected by my time zone?
- No. All dates are treated as whole calendar days at local midnight, so there is no timezone drift and the number of days between two dates is always accurate.
- Can it count the number of days between two dates?
- Yes. Switch to the Days between two dates mode and enter both dates. It shows the total days, total weeks, a weeks-and-days split, and a years/months/days breakdown, even if you enter the dates in reverse order.