What this calculates
Enter two dates, and this counts the days between them — then shows the same span in years, months and days, in weeks and days, and split into weekdays and weekend days. Turn on "Include end date" to count the last day as well.
Weekdays are Monday to Friday. Public holidays are not taken out, since they differ by country, state and year.
The formula
Days between
days = (end date − start date) ÷ one dayIncluding the end date
days = days between + 1Weeks
weeks = days ÷ 7, with the remainder as daysWeekdays
5 for each whole week, plus the leftover days that fall Monday to FridayThe years, months and days count whole years first, then whole months, then the days left. Where a month is too short for the start day — 31 January plus one month — the count lands on that month's last day. Every day is a calendar day in UTC, so time zones and daylight saving never add or lose one.
Worked example
Counting 31 December too gives 365 days — 261 weekdays, since that extra day is a Thursday.
When to use it, and the mistakes to avoid
Use it to count down to an event, to work out a notice period or a loan's days, to count the length of a trip or a leave, and to find how many weekdays a span holds.
The mistakes that cost the most:
- Including or leaving out the end date by accident. The days between 1 and 3 October are two; the days of a trip from 1 to 3 October are three. Decide which you mean.
- Treating every month as 30 days. Months run 28 to 31 days, so count real dates: 31 January to 1 March 2026 is 29 days, not 30.
- Forgetting leap years. 2024 had 366 days. Over long spans the leap days add up: 15 August 1947 to 15 August 2026 is 28,855 days, 20 more than 79 × 365.
- Reading weekdays as working days. Public holidays and your own days off are not taken out here.
FAQ
How many days are there between two dates?
Count from the start date up to the end date: the start is day zero. From 1 January to 31 December 2026 is 364 days. Turn on 'Include end date' to count the last day too, which makes it 365.
Should I include the end date?
It depends on what you are counting. For the gap between two dates - how long until an event - leave it off. For a span where both the first and last day happen - a trip, a leave, a course from the 1st to the 3rd - turn it on: that is two nights but three days.
How many weekdays are between two dates?
Every whole week holds five weekdays, Monday to Friday, and the days left over are checked one by one. 2026 has 261 weekdays counting both 1 January and 31 December - it starts and ends on a Thursday.
Does this take out public holidays?
No. Public holidays differ by country, by state and from year to year, so weekdays here are simply Monday to Friday. Subtract the holidays that apply to you for a count of working days.
How are leap years handled?
Every real day is counted, so a leap year's 29 February is in. 1 January 2024 to 1 January 2025 is 366 days; 1 January 2026 to 1 January 2027 is 365.
Why does 31 January to 1 March show one month and one day?
A month after 31 January is taken as the last day of February, since February has no 31st. From there to 1 March is one more day. The total is 29 days in 2026.