Free date difference calculator
Pick a start and end date to see the total day count, week breakdown, and calendar years/months/days. All math runs in this tab — no server upload.
How to use this tool
- 1
Open date difference
Pick a start date and an end date.
- 2
Adjust inclusive option
Enable “include end date” when both boundary days should count.
- 3
Read the breakdown
Note total days, weeks, and calendar years/months/days.
Quick facts
| Runs locally? | Yes — date math runs entirely in your browser. |
|---|---|
| Is anything uploaded? | No. Dates never leave this tab. |
| vs age calculator? | Age counts from birth to today; this compares any two dates you pick. |
| Inclusive days? | Off by default (exclusive span). Turn on “include end date” to count both endpoints. |
Top use cases
- Find days, weeks, and calendar span between two dates — runs locally in your browser.
- Runs locally?: Yes — date math runs entirely in your browser.
- Is anything uploaded?: No. Dates never leave this tab.
- vs age calculator?: Age counts from birth to today; this compares any two dates you pick.
- Inclusive days?: Off by default (exclusive span). Turn on “include end date” to count both endpoints.
FAQ
Exclusive vs inclusive?▾
Exclusive: Jan 1 → Jan 3 = 2 days. Inclusive (+1): counts both Jan 1 and Jan 3 → 3 days.
Leap years?▾
Total days follow the Gregorian calendar, including Feb 29 in leap years.
Time zones?▾
Date-only inputs — no time-of-day or zone conversion. For zones use the time zone converter.
Business days?▾
Not in this tool — it counts all calendar days including weekends.
Backward end date?▾
Allowed — results show absolute span; use Swap to flip dates quickly.
Offline?▾
Works offline after the page loads.