Date Difference Calculator
Days, weeks, months and business days between two dates. Runs in your browser.
About this date difference calculator
This date difference calculator tells you how long it is between two dates in years, months and days, and in total days, weeks, hours, minutes and seconds. It also counts business days, with your own weekend and holiday list.
Your weekend doesn't have to be Saturday and Sunday. Pick Friday and Saturday for Bangladesh and much of the Gulf, Friday only, Sunday only, or any days you like. Paste your public holidays and they are left out too.
A second mode adds or subtracts days, weeks, months, years or business days from a date. The maths uses plain calendar dates, so time zones and daylight saving can't shift the answer by a day.
Features
Years, months and days
The calendar difference the way people say it, such as 7 months 18 days, plus the total in days, weeks, months, hours, minutes and seconds.
Business days with any weekend
Presets for Saturday + Sunday, Friday + Saturday, Friday only and Sunday only, or toggle each weekday yourself.
Your holidays
Paste dates one per line as YYYY-MM-DD with an optional label. Holidays that fall on a weekend or outside the range aren't counted twice.
Include end date
One tick adds the end date, for inclusive ranges like a hotel stay or a leave application from the 1st to the 5th.
Add or subtract
Move a date by years, months, weeks and days, or by a number of business days for deadlines. The weekday of the result is shown.
Dates in either order
If the end date is earlier, you still get the difference and a note saying it runs backwards. A swap button flips them.
How to use the date difference calculator
- 1Pick a start date and an end date, or switch to Add / subtract.
- 2Choose whether to include the end date, your weekend days and any holidays.
- 3Read the difference, totals and business days, or the new date.
When to use it
Notice periods and deadlines
"Reply within 10 working days" from Monday 2 November 2026 means Monday 16 November with a Saturday and Sunday weekend.
Leave and payroll
Count the working days in a month for pay, or the days of annual leave a trip will use.
Projects and contracts
Find the end date 90 days after signing, or the business days left before launch.
Countdowns
Days until an exam, a wedding or a visa expiry. For your own age down to the day, the age calculator adds the next birthday countdown.
How do I calculate the number of days between two dates?
Subtract the earlier date from the later one in whole days. From 15 March 2026 to 2 November 2026 is 232 days. If both the first and last days count, add one: 233 days.
Doing this by hand means counting the days left in the first month, every full month in between, and the days in the last month, minding leap years. The calculator turns each date into a day number and subtracts, so leap years are handled without any special case.
How are months and years counted?
Full calendar months are counted first, then the days left over. 15 March to 2 November is 7 full months (to 15 October) plus 18 days.
When a month is too short for the start day, the month ends on its last day. So 31 January plus one month is 28 February, or 29 in a leap year. Adding a month to 31 March gives 30 April for the same reason.
How many working days are in a year?
2026 has 365 days and 104 weekend days, so it has 261 working days before public holidays, with either a Saturday + Sunday or a Friday + Saturday weekend. Subtract your country's public holidays that fall on weekdays to get the real figure.
The count includes the start date. The end date counts only if you tick Include the end date, which matches how most spreadsheets and deadline rules work.
How does adding business days work?
The start date itself is not counted. Each step moves one day forward and only counts it if it is not a weekend day or a listed holiday. Ten business days from Monday 2 November 2026 lands on Monday 16 November.
Subtracting works the same way backwards, which helps when you need to know the last day to post something so it arrives by a deadline.
Why use Mavros
| Mavros | Typical upload sites | |
|---|---|---|
| Weekend | Any days, with Friday + Saturday preset | Saturday + Sunday only |
| Holidays | Paste your own list with labels | One country's list, or none |
| Output | Y/M/D plus days, weeks, hours, minutes, seconds | Days only |
| Add business days | Forward or back, weekday shown | A separate tool |
| Time zones | Plain dates, no day shift | Can be off by one around DST |
| Privacy | Runs in your browser | Server form submit |
Tips
- Check whether a deadline says calendar days or working days. The answer can differ by a week or more.
- Keep a holiday list for your country in a note and paste it in each time. Labels after the date are ignored.
- Dates are entered with your device's date picker but stored as plain YYYY-MM-DD values, the ISO 8601 format.
- Working with timestamps from a log file? Convert the Unix timestamp to a date first, then compare.
- If the two dates are in different time zones, convert both to one zone with the time zone converter before counting.
Questions
How many days are there between two dates?
Pick the two dates above and the total appears instantly. By hand, subtract the earlier date from the later one in days; from 15 March to 2 November 2026 that is 232 days.
Does the calculator include the end date?
Not by default, so 1 to 5 June counts as 4 days. Tick Include the end date to make it 5. Use that for inclusive ranges like leave or bookings.
How do I count business days excluding weekends and holidays?
Set your weekend days, paste your holidays as YYYY-MM-DD, and read the Business days box. It subtracts weekend days and any listed holiday that lands on a working day.
Can I use a Friday and Saturday weekend?
Yes. Choose Friday + Saturday, used in Bangladesh, Saudi Arabia, Kuwait and Qatar among others, or click any weekday to make it part of the weekend.
How do I add 90 days to a date?
Switch to Add / subtract, pick the start date and enter 90 in Days. From 30 October 2026, 90 days later is 28 January 2027.
Why does adding one month to 31 January give 28 February?
February has no 31st, so the date moves to the last day of the month. This is the usual rule in banking and in spreadsheets.
Are leap years handled?
Yes. Leap years follow the Gregorian rule: every fourth year, except century years not divisible by 400. So 2000 was a leap year and 2100 will not be.
Can I calculate dates in the Hijri or Bangla calendar?
Not here, since this tool uses the Gregorian calendar. Convert a Hijri or Bangla date with the calendar converter first, then count the days.