Days Between Dates Calculator
Count the days, weeks, months and business days between two dates — or add and subtract days, weeks, months or working days from a date — with the working shown.
Days Between Dates
Working
How to use the date calculator
Choose Days between dates to measure the gap between a start and an end date. You get the total in days, the same span as weeks and days, months and days, and years, months and days, plus the number of business days for the weekend you pick. If the end date is earlier than the start, the two are swapped and the result is the same. Tick Include the end date when both the first and last day should count.
Choose Add or subtract to move forward or back from a date by a number of days, weeks, months, years or business days — for example, “30 days from today” or “10 working days before the deadline”. For business days you can pick the weekend and list any public holidays to skip. Every result shows the working, and the settings are kept in the page address so you can bookmark or share them.
The formulas
Each date is turned into a day number on the Gregorian calendar, so a difference is plain subtraction:
days = day number(end) − day number(start) (+ 1 if the end date is included)
weeks and days = days ÷ 7, remainder in days
business days = full weeks × working days per week
+ working days among the leftover days
− holidays that fall on working days Months are counted in whole calendar months from the start date (15 January → 15 February → 15 March…), and the days after the last whole month are added. When a month does not have the start day — 31 April, 30 February — the last day of that month is used. Adding months or years uses the same rule; adding days or weeks never needs it.
Worked example
A project runs from Monday, 2 March 2026 to Tuesday, 30 June 2026.
- Days: 2 March + 3 months = 2 June (92 days), then 28 more days to 30 June — 120 days, or 3 months and 28 days.
- Weeks: 120 ÷ 7 = 17 weeks and 1 day.
- Business days (Saturday–Sunday weekend): 17 full weeks × 5 = 85, and the one leftover day is a Monday, so 86 business days.
- If the last day, 30 June, is a working day of the project too, tick Include the end date: the span becomes 121 days (17 weeks and 2 days, 3 months and 29 days) and 87 business days.
Adding works the same way in reverse. 10 business days after Thursday, 24 September 2026 is Thursday, 8 October 2026: counting forward from the day after the start, two weekends (4 days) are skipped, so the result is 14 calendar days later.
Weekends around the world
Business days depend on which days are the weekend where the work happens:
- Saturday and Sunday — the most common weekend worldwide. The UAE federal government moved to it from Friday–Saturday on 1 January 2022, and federal employees also finish at midday on Friday. UAE private-sector employers set their own weekly rest days (the law requires at least one paid rest day a week), so check your contract.
- Friday and Saturday — the official weekend in Saudi Arabia since 2013, and common in several other Gulf countries.
- Friday only or Sunday only — for six-day working weeks, which are common in retail, hospitality, construction and some other jobs.
The calculator counts whole days only: a half-day Friday counts as a working day. It does not know public holidays, which differ by country and employer and, for Islamic holidays, are often confirmed only shortly before by moon sighting — add them yourself once the dates are announced.
Common mistakes
- Off-by-one errors. Monday to Friday is 4 days apart but 5 days inclusive. Decide whether you are measuring a gap or counting days used.
- Treating a month as 30 days. 30 days after 31 January is 2 March (in 2026), not the end of February. Use the “months” unit when you mean calendar months.
- Forgetting holidays. A notice period or delivery estimate in business days usually excludes public holidays too.
To find someone’s exact age, use the age calculator. To convert a number of days into hours or weeks, see days to hours and weeks to days. Legal and contractual deadlines can follow their own counting rules, so check them for anything important.
Frequently asked questions
How many days are there between two dates?
Subtract the earlier date from the later one on the calendar. From 2 March to 30 June 2026 that is 120 days: the start day counts and the end day does not, the same way “one day after Monday” is Tuesday. Tick Include the end date to count both days, which gives 121.
Should I include the end date?
Include it when both the first and the last day are “used”, such as a hotel stay counted in days, a leave request from Monday to Friday (5 days), or an event that runs through the end date. Leave it out when you are measuring elapsed time — how long until a deadline, or how many nights you stay.
How are business days counted?
Every day in the range is checked against the weekend you choose. Whole weeks contribute 5 working days (6 with a one-day weekend), and the leftover days are checked one by one. Any holiday dates you add that fall on working days are then subtracted. Public holidays are not included automatically.
Which weekend does the UAE use?
The UAE federal government moved from a Friday–Saturday weekend to Saturday–Sunday on 1 January 2022, with Friday a half working day for federal staff. Private-sector employers set their own weekly rest days, so check your contract. This calculator counts a half-day Friday as a working day.
What is 31 January plus one month?
There is no 31 February, so the result moves to the last day of February: 28 February, or 29 February in a leap year. The working says when this happens. Adding days or weeks never needs this rule, because every day exists.
Does the calculator handle leap years and daylight saving time?
Yes. It counts whole calendar days on the Gregorian calendar, so every 29 February is included and clock changes cannot add or lose a day. Dates from year 1 to 9999 are supported.