Please enter two valid dates.
About the Date Calculator
This date difference calculator counts the exact amount of time between a start date and an end date. It reports the gap as full years, months and days, and also as total days, weeks, and weekdays — useful for counting business days between two dates at a glance.
Common uses include counting days until a deadline, working out the length of a contract or project, checking how many days you have been at a job, calculating notice periods, tracking pregnancy weeks, working out interest periods, and finding out how many days remain until a holiday, wedding or exam. Because the tool works with real calendar dates, leap years and 28/29/30/31-day months are always handled correctly.
How the Difference Is Calculated
The calculator counts calendar days between the two dates, automatically accounting for leap years and the different lengths of months. The years/months/days breakdown counts forward from the start date: first whole years, then whole months, then remaining days. The weekday count excludes Saturdays and Sundays but does not account for public holidays, which vary by country.
Example: From 1 January 2026 to 15 September 2026:
8 whole months (1 Jan → 1 Sep) plus 14 days = 8 months, 14 days — a total of 257 days, or 36 weeks and 5 days, of which 183 are weekdays.
Handy Time-Unit Reference
| Period | Days | Weeks |
|---|---|---|
| 1 week | 7 | 1 |
| 1 fortnight | 14 | 2 |
| 1 common year | 365 | 52 weeks + 1 day |
| 1 leap year | 366 | 52 weeks + 2 days |
| 1 quarter (Jan–Mar 2026) | 90 | 12 weeks + 6 days |
| 180 days (visa rule of thumb) | 180 | 25 weeks + 5 days |
Days in Each Month
Month lengths are the main reason date arithmetic is tricky. A quick reference:
| 31 days | 30 days | 28 / 29 days |
|---|---|---|
| January, March, May, July, August, October, December | April, June, September, November | February (29 in leap years: 2024, 2028, 2032…) |
Old rhyme: "Thirty days hath September, April, June and November…" — or use this calculator and never worry about it again. For the leap-year rules in detail, see our leap year guide.
Counting Business Days
The "Weekdays (Mon–Fri)" figure is a quick way to estimate working days for project plans, delivery windows, notice periods and payroll. Remember that public holidays are not excluded — subtract any holidays that fall within your range in your country. For example, a 30-day month typically contains 20–22 weekdays before holidays are removed.
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