How it works
Count the days between two dates and see the calendar difference in years, months and days, plus total weeks and hours.
Enter a start and end date. The calculator returns the exact number of days, total weeks, months and years, the whole calendar difference (years, months and days) and the total hours. Use it for deadlines, countdowns, ages, notice periods and project durations. Both dates are calendar dates in the Gregorian calendar.
Formula
Total days = end − start. Calendar difference: count whole months first (clamped to the length of the month, e.g. 31 Jan + 1 month = 28/29 Feb), then add the remaining days.
start/end- Start and end dates (date)
Examples
- 31 January to 1 March 2024Start 2024-01-31 · end 2024-03-0130 days · 1 month 1 day · 720 hours
- 15 May 2000 to 26 September 2026Start 2000-05-15 · end 2026-09-269,630 days · 26 years 4 months 11 days
Frequently asked questions
How is the calendar difference counted?
It counts whole months from the start date, clamping the day to the end of shorter months, then adds the leftover days. That is how contracts and ages are usually expressed.
What if the end date is before the start date?
The calculator requires the end date to be on or after the start date; swap the dates for a countdown in the other direction.
Does the day count include both endpoints?
No. The count is the difference between the dates; add one day to include both endpoints.
How to read the result
Use total days for precision and the calendar difference for the everyday “X years, Y months, Z days” phrasing.
Limitations
Gregorian calendar dates only, with no time-of-day or working-day adjustments (business days are a separate calculator).
Source: Gregorian calendar arithmetic with month-length clamping.