Date Difference Calculator
Difference
358 days
- Years, months, days0y 11m 24d
- Weeks51 weeks 1 days
- Whole months11
- Counting both ends359 days
How this was worked out
- Start excluded, end included2026-01-01 to 2026-12-25 counts 2026-12-25 and not 2026-01-01 = 358 days
- Split into weeks358 ÷ 7 = 51 weeks and 1 days
- Counted in months2026-01-01 plus 11 months lands on 2026-12-01, then 24 days more
- Weekends removed358 − 102 Saturdays and Sundays = 256 working days
The start date is excluded and the end date included, which is the convention commercial and delivery terms use and the one the business days calculator on this site follows — 1 January to 2 January is one day. If you need the inclusive count, the “counting both ends” row is that figure. Working days remove Saturdays and Sundays only: public holidays vary by country, state and year, so use the business days calculator to subtract them and to pick a different weekend. Everything is counted as whole calendar days in UTC, so a daylight saving change cannot turn a day into 23 or 25 hours and shift the total by one; the hours figure is 24 per calendar day for the same reason. Whole months cannot be recovered by dividing days by 30 — a month here is a real calendar month, 28 to 31 days long.
One span, several honest answers
How long is it between two dates? The question has more than one correct answer, and which one you want depends on why you are asking. A landlord wants months. A project manager wants working days. A contract wants a plain count of days. This calculator gives all of them at once for any two dates: total days, whole weeks plus a remainder, whole months, the years-months-days breakdown, and the number of working days in between.
Typical uses are notice periods, tenancy and contract lengths, project durations, visa and residency day counts, and settling the perennial argument about how long ago something happened.
A worked example: 1 January to 25 December 2026
One span, five ways of stating it.
| Measure | Answer |
|---|---|
| Total days | 358 |
| Weeks and days | 51 weeks and 1 day |
| Years, months and days | 0 years, 11 months, 24 days |
| Whole months elapsed | 11 |
| Working days | 256 |
The five different-looking numbers describe the same span. 358 days is not "about 12 months" — it is 24 days short of a year, which is exactly the kind of gap that matters when a notice period or a lease is being counted. The working-day figure is what remains once Saturdays and Sundays are removed.
Reversing the dates gives the same magnitude with a note that the second date is earlier. The tool does not silently return a negative, because a negative number of days is rarely what anyone wanted to see.
How each figure is derived
Total days is the plain difference between the two dates in UTC, divided by 24 hours and rounded. Working in UTC matters: a local-time date crossing a daylight-saving boundary makes a whole day 23 or 25 hours long, which is enough to shift a rounded day count by one at exactly the wrong moment.
Weeks are total days divided by seven, floored, with the remainder shown separately. The calendar breakdown counts the largest whole number of months that does not overshoot — clamping the day to the length of the destination month, so 31 January plus one month is 28 February — and then measures the leftover days from there. Working days exclude Saturdays and Sundays, counting the end date and not the start.
What is counted, and what is not deducted
Both ends are treated as whole calendar days with no time of day, so the count does not change during the day and does not depend on your time zone. The start date is excluded and the end date included, which is the convention used for commercial and delivery terms.
The working-day figure excludes weekends only. Public holidays are not deducted, because they vary by country, state and year and any built-in list would be quietly wrong; the dedicated business days calculator on this site lets you subtract them and lets you pick a different weekend.
Note also that the first and fourth rows of the table above cannot be reconciled by a fixed multiplier. A month is anywhere from 28 to 31 days, so dividing 358 by 30 will not reproduce the month figure and never could.
Counting the first day, whole months and leap years
Should the first day be counted?
Not here. The start date is excluded and the end date included, so 1 January to 2 January is one day. If you need the inclusive count — the number of days a thing was in effect, including both ends — add one to the total.
Why is the months figure not just days divided by 30?
Because months genuinely differ in length. Counting whole calendar months from a fixed anchor is the only method that survives February, and it is the method a lease or a subscription actually uses when it says "monthly".
Are leap years handled?
Yes, automatically. Every count is a real calendar difference, so 29 February is included whenever it falls inside the range — which is why a year-long span can be 365 or 366 days depending on where it starts.
Last reviewed 27 August 2026