Date Calculator
Add or subtract days from a date, or count the days and weeks between two dates.
1 min read
Runs in your browser — your text and files never leave your device.
Negative numbers count backwards.
Two date jobs in one place: "what is 90 days from today?" and "how long is it between these two dates?" Both are answered exactly, including across leap years.
How to use it
- Choose whether you are adding days or measuring between dates.
- Enter the date or dates — a negative number of days counts backwards.
- Press Calculate.
Good to know
- The result includes the weekday, which is usually what you need when booking something.
- Counting between two dates gives the exact number of days, plus the same span in weeks.
Related tools: Age Calculator · Time Zone Converter
Frequently asked questions
Does the difference include the end date?
It is the number of days between the two dates. If you need a deadline day counted, check the weekday the calculator shows.
Can it handle dates far in the past or future?
Yes, within the range JavaScript dates support — several thousand years either way.