Date Calculator
Find out exactly how many days separate two dates, how many working days that is, or what date it will be 90 days from now. Results update as you type.
🔒 Runs in your browser. Nothing is uploaded.
How to use
- Choose "Days between dates" and pick a start and an end date. Use the "Today" buttons to fill in the current date.
- Check "Include the end date" if both days should count, for example for hotel nights vs. rental days.
- Read the total days, the weeks-and-days breakdown, the calendar difference and the number of weekdays.
- Switch to "Add or subtract" to move a date forward or back by days, weeks, months or years.
Examples
Deadline countdown
Set today as the start and the deadline as the end to see how many days are left.
Return or warranty periods
Add 30 days to a purchase date to find the last day you can return an item.
Age or tenure
Enter a birth date or start date and today to get the exact years, months and days.
Frequently asked questions
Are both dates counted?
By default the difference is the number of nights between the dates: Jan 1 to Jan 3 is 2 days. Check "Include the end date" to count both, giving 3.
How are months calculated when adding?
Adding one month keeps the same day of the month when possible. If the target month is shorter, the last day is used: Jan 31 + 1 month = Feb 28 (or 29 in a leap year).
What counts as a weekday?
Monday to Friday. Public holidays are not excluded because they differ by country.
Does it handle leap years and daylight saving time?
Yes. Calculations use calendar dates at midday so daylight-saving changes never shift a result by a day, and leap days are counted correctly.