Date Difference Calculator — Days Between Two Dates
Pick two dates and see the number of days between them, the weekdays, the weeks and the calendar breakdown — then add or subtract any number of days from a date.
— total days
— as calendar years, months and days
— weeks — weekdays (Mon–Fri)
—
What this calculator does
It answers two everyday questions about dates. The first panel measures the distance between two dates: how many whole days separate them, how many of those are weekdays, and how the span reads as calendar years, months and days. The second panel moves a date forward or backward by a number of days, which is how you check a deadline, a return window or an invoice due date.
How the days are counted
The total is the end date minus the start date, so the same day is 0 and the next day is 1. Each date is read as a calendar day in UTC, which is what keeps the count free of daylight-saving surprises: a clock change cannot add or remove a day from the total. The weekday count includes Monday to Friday in the interval from the start up to but not including the end date, and treats Saturday and Sunday as non-working. Public holidays are deliberately not subtracted, because they vary by country and year — remove them yourself when you need true working days.
The calendar breakdown is not the total divided by an average month. It walks the actual dates: from 1 January 2026 to 15 March 2027 it reports 1 year, 2 months and 14 days, which is what a person means when they say “about fourteen months”. The total-day figure remains the precise measure.
Examples
| From | To | Total days | Weekdays |
|---|---|---|---|
| 2026-01-01 | 2026-01-31 | 30 | 22 |
| 2026-01-05 (Mon) | 2026-01-12 (Mon) | 7 | 5 |
| 2024-02-01 | 2024-03-01 | 29 (leap year) | 21 |
Frequently asked questions
Is the day count inclusive of the start or end date?
The total is “end minus start”, so 1 January to 1 January is 0 days and 1 January to 2 January is 1 day. That is the convention most systems use for the elapsed difference. If you want to count both endpoints — the number of dates the period touches — add 1 to the total.
How are the weekdays worked out?
Weekdays are the Monday-to-Friday days in the interval from the start date up to but not including the end date. Saturday and Sunday are never counted. No public-holiday calendar is applied, because holidays differ by country and year; subtract those yourself if you need working days.
Why is the number of days not simply the months times thirty?
Because months have different lengths and February changes in a leap year. This tool counts real calendar days, so 1 January to 1 March is 59 days in 2026 and 60 days in 2024. The calendar breakdown — years, months and days — is computed on the actual dates, not on an average month.
Does daylight saving time change the result?
No. The dates are interpreted as calendar days in UTC, so a clock change cannot add or remove a day. The result is a count of whole days, which is independent of any time zone.
Can I calculate a date in the future or the past?
Yes. Use the add/subtract panel to move a date forward or backward by any number of days — useful for deadlines, return windows, notice periods and invoice due dates. Negative amounts move backwards.
Is anything sent to a server?
No. The whole calculation is plain date arithmetic in your browser; nothing leaves the page.
Go deeper
Longer explanations of the problems this tool solves:
Sources
- ISO 8601, Date and time format — the calendar conventions used for the day arithmetic.
- RFC 3339, Date and Time on the Internet: Timestamps.
Everything runs in your browser — nothing you type is uploaded.