Date Calculator

Count the days between two dates, including weekdays and weekends, or add and subtract days, weeks, months and years from a date.

Days between two dates

Add or subtract from a date

How to count the days between two dates

  1. Enter a Start date and an End date. To begin with they are set to today and 31 December of this year.
  2. The number of days appears straight away, with the same period broken down below it.
  3. Tick Include the end date when both the first and the last day should be counted.

If the end date is earlier than the start date, the result is shown with a minus sign, so you can count backwards as well – for example, how many days ago something happened.

What the results mean

  • Days: the difference between the two dates. It works like counting nights in a hotel: from Monday to Friday is 4 days. With Include the end date ticked, one day is added so that both ends count, which is what you want for leave, events and rental periods – Monday to Friday is then 5 days.
  • Years, months, days: complete calendar months first, then the remaining days, using the same rules as the Age Calculator.
  • Weeks and days: the total number of days split into whole weeks and the days left over.
  • Weekdays (Mon–Fri) and Weekend days: how many of the counted days fall on Monday to Friday and how many on Saturday or Sunday. The end date is only counted when Include the end date is ticked.
  • Hours / minutes: the days times 24 and times 1,440. These are calendar days, so the one-hour shifts of daylight saving time are not taken into account.

Adding or subtracting from a date

The second calculator finds a date a given time before or after another one. Choose the date, + add or − subtract, a whole number and a unit, and the resulting date appears with its weekday.

  • days and weeks move by exactly that many calendar days (a week is 7 days).
  • business days (Mon–Fri) counts only weekdays, starting from the day after the chosen date, so the result always falls on a weekday. Friday 6 November 2026 plus 10 business days is Friday 20 November 2026, and a Saturday plus 1 business day is the following Monday.
  • months and years keep the same day of the month. If the target month is too short, the result is its last day: 31 January 2026 plus 1 month is 28 February 2026, and 29 February 2024 plus 1 year is 28 February 2025. This is the same rule as the EDATE function in Excel and Google Sheets.

Note that adding and subtracting months is not always reversible: 28 February 2026 minus 1 month is 28 January 2026, not the 31 January you started from.

Worked examples

  • Countdown: from 5 November 2026 to 25 December 2026 is 50 days – 7 weeks and 1 day, of which 36 are weekdays and 14 weekend days.
  • A week’s holiday: Monday 13 July to Friday 17 July 2026 is 4 days, or 5 with Include the end date ticked.
  • A whole year: 1 January to 31 December 2026 with the end date included is 365 days, 261 weekdays and 104 weekend days.
  • Deadline: 90 days after 5 November 2026 is Wednesday 3 February 2027.
  • Notice period: 6 weeks before Thursday 5 November 2026 is Thursday 24 September 2026.

Leap years and month lengths

The calculator uses the Gregorian calendar. Months have 28 to 31 days, and February has 29 days in a leap year. A year is a leap year if it is divisible by 4, except for century years, which must be divisible by 400: 2000 and 2024 were leap years, 2028 will be the next one, and 2100 will not be. All of this is handled automatically, so a period that crosses 29 February simply contains one more day.

Tips

  • Contracts and official deadlines don’t all count days the same way – some include the first day, some exclude it, and some move a deadline that falls on a weekend. Check the wording, then use Include the end date to match it.
  • Public holidays are not taken out of business days or weekdays, because they differ by country and region. Subtract them yourself, or add a day for each holiday in the period.
  • To count down to an event, set the start date to today and the end date to the event; the result tells you how many days are left.

FAQ

Why is Monday to Friday 4 days and not 5?

By default the calculator gives the difference between the dates, which doesn’t count the end date itself. Tick Include the end date if you are counting days on which something happens.

Does daylight saving time change the result?

No. The calculator counts calendar days, so a day with a clock change is still one day.

Can I use dates far in the past?

Yes, but historical records may not match. The calculator applies the Gregorian calendar to all years, while many countries used the Julian calendar until 1582 or later.

How do I find someone’s exact age?

The Age Calculator shows age in years, months and days, plus a countdown to the next birthday.