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Date Difference Calculator

Count the days, weeks and months between two dates.

I want to

Time between the dates

92 days

3 months

Weeks
13 wk 1 d
Working days (Mon–Fri)
66
Hours
2,208
Minutes
132,480

When to use it

Use this calculator to count the days between two dates, or to find a date a set number of days, weeks, months or years away. It is useful for deadlines, notice periods, pregnancy and travel planning, project schedules, or simply counting down to a birthday or holiday.

How to use it

The calculator has two modes under I want to.

Count days between dates

  1. Choose the Start date and the End date. They start as today and three months from today.
  2. Tick Include the end date (count both days) if both the first and last day should count.
  3. Read the total days, plus months, weeks, Working days (Mon–Fri), hours and minutes.

Add or subtract days

  1. Choose the Start date.
  2. Under Add or subtract, pick Add or Subtract.
  3. Enter the Amount and choose the Unit: days, working days, weeks, months or years.
  4. Read the resulting date, including the day of the week.

Worked example

A project runs from Monday 1 March 2027 to Tuesday 1 June 2027. The calculator shows 92 days, which is 3 months. Of those, 66 are working days. Tick Include the end date and both totals go up by one: 93 days and 67 working days, because 1 June is a Tuesday.

Next, you need to reply to a letter within 30 working days of 1 March 2027. Switch to Add or subtract days, enter 30 and choose working days. The deadline is Monday 12 April 2027. If you had chosen 30 plain days instead, it would be 31 March.

Tips

  • Read the exact wording of deadlines. “Within 14 days” and “14 working days” can be weeks apart.
  • Check holidays for working days. Take off any public holidays in your range, since the calculator counts all weekdays.
  • Use weeks for pregnancy and training plans. The weeks figure shows full weeks plus spare days, such as 13 weeks 1 day.

Counting down

To count down to an event, leave the start date as today and set the end date to the event. Come back any day and the count updates, because the start date always opens on the current day.

Common mistakes

  • Counting the start day by accident. Most deadlines start counting from the next day. The calculator does this by default.
  • Assuming all months are 30 days. Months range from 28 to 31 days. Use the months unit rather than multiplying 30 days.
  • Forgetting time zones for travel. The calculator counts calendar days. Long flights across time zones can make a trip feel a day shorter or longer.

Frequently asked questions

Should I include the end date?

It depends on what you are counting. For "how long until" questions, leave it off. For things like hotel nights or a holiday where both the first and last day count, tick Include the end date to add one day.

Does the working days count skip public holidays?

No. It counts Monday to Friday only and does not know about public holidays, which differ by country and region. Subtract any holidays that fall in your date range yourself.

How does adding months work at the end of a month?

Adding a month keeps the same day number where possible. If that day does not exist, the date moves to the last day of the month. For example, 31 January plus one month gives 28 February, or 29 February in a leap year.

Can I count backwards?

Yes. In Count days between dates, the end date can be earlier than the start date, and the result shows a minus sign. In Add or subtract days, choose Subtract to go back in time.

Does it handle leap years?

Yes. It uses the real calendar, so 29 February is counted in leap years.

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