Days between two dates
Add or subtract days
Countdown to a date (D-day)
How to use
- To count days between two dates, enter a start and an end date. Tick the box to include the end date if both days should count.
- To find a date in the future or past, enter a start date and a number of days. Use a minus sign to go back.
- For a countdown, enter the target date to see how many days are left, or how many have passed.
- Read the details under each result for the same span in weeks, months and weekdays.
Three date calculations in one place
Planning often comes down to counting days. How many days until the exam? What date is 90 days after the contract starts? How many working days does the project have? This page answers all three with separate calculators, and each result also shows the span in weeks, months and weekdays.
Days between two dates
Enter a start and end date to get the number of days between them. The result is also shown as weeks plus days, calendar months plus days, and the number of weekdays. If the end date is before the start date, the result is negative so you can see which way the difference runs.
Whether to include the end date is the most common source of confusion. A hotel stay from the 1st to the 5th is four nights; a conference from the 1st to the 5th is five days. The checkbox lets you choose the rule that matches your case.
Adding and subtracting days
Enter a date and a number of days to find the resulting date and its day of the week. This is useful for deadlines such as “within 30 days of delivery”, notice periods, or medical schedules. Leap years are handled automatically, so adding one day to February 28, 2024 gives February 29.
D-day countdown
Enter a target date to see a countdown such as D-12, or D+30 for a date that has passed. For anniversaries, the option to count the start date as day 1 shows the number of the current day; 99 days after the start is then the 100th day.
Example
From January 1 to March 15, 2024 is 74 days: 10 weeks and 4 days, or 2 months and 14 days. Of those days, 55 are weekdays when both ends are counted. Adding 100 days to January 1, 2024 lands on April 10, 2024, a Wednesday.
Time zones
The calculator works with calendar dates rather than timestamps, so it never shifts a result by a day because of your time zone or daylight saving time. “Today” is taken from your device’s clock and calendar.
Frequently asked questions
- Does the day count include the start and end dates?
- By default it counts elapsed days, so Monday to Tuesday is one day, as in a one-night hotel stay. Tick Include the end date to count both calendar dates, as you might for a two-day event. Check which rule applies to your situation.
- How are weekdays counted?
- Weekdays are Monday to Friday, and both the start and the end date are included if they fall on a weekday. Public holidays are not removed because they differ by country and region.
- How are months counted between dates?
- The calculator counts whole calendar months and then the leftover days. From January 15 to March 20 is two months and five days. When the start day does not exist in a month, the last day of that month completes the month.
- What does D-day mean?
- D-day is the target date. D-10 means ten days before it, and D+10 means ten days after. The countdown is a popular way to track exams, launches and trips.
- What does "count the start date as day 1" do?
- For anniversaries some people count the first day as day 1, so the 100th day falls 99 days after the start. Tick the box to use that convention.
- Can time zones change the result?
- No. Dates are treated as calendar days, so the result is the same whatever your device's time zone or the time of day.