A date calculator finds either the gap between two dates in days (and weeks, months, years) or the resulting date after adding or subtracting a number of days. Use Mode A to count days between two dates, or Mode B to move forward or backward from a starting date.
Choose a mode with the buttons at the top.
| Task | Input | Result |
|---|---|---|
| Days between | Jan 1, 2026 to Jun 19, 2026 | 169 days (24 wks, 1 day) |
| Days between | Jun 19, 2026 to Dec 31, 2026 | 195 days (27 wks, 6 days) |
| Add days | Jun 19, 2026 plus 90 days | September 17, 2026 |
| Subtract days | Jun 19, 2026 minus 30 days | May 20, 2026 |
Deadlines, countdowns, project planning, and figuring out exactly how long ago that embarrassing thing happened: all good uses.
The calculator counts calendar days, not business days. A 7-day week is counted as exactly 7 days regardless of holidays or weekends. The end date itself is not included in the count (just as age is measured from the day of birth, not through it). Leap years are handled automatically, so February 29 is a valid date in any leap year.
Select the 'Days between dates' mode, enter your start date and end date, and the result appears instantly. The answer includes weeks and remaining days.
Select the 'Add or subtract days' mode, enter a starting date, then type the number of days to add. To subtract, enter a negative number such as -30.
The count measures the gap between the two dates but does not include the end date itself. For example, Jan 1 to Jan 3 is 2 days, not 3.
Yes, completely free, no signup needed, and it runs entirely in your browser. Nothing is stored or sent anywhere.