Use this free date calculator to add days, weeks, months or years to a date, or to take them away. The start date is today, so it is quick to find the date 30 days from today, 90 days ago or 3 months from now. You get the new date, the day of the week, the day of the year, and how many weekdays and weekend days are in the period. Tables show the date 7 to 365 days from today and ago, 1 to 52 weeks from today and 1 to 24 months from today, and a panel shows today's date. It is free and instant, and your dates stay in your browser.
How to add or subtract days, weeks, months and years
Choose a start date, decide whether to add or subtract, and type how many years, months, weeks and days you want to move. You get the new date and the day of the week it falls on. You can use any of the four boxes on their own or together.
Tuesday, 29 December 202691 days is 13 weeks. Counting 13 weeks from Tuesday 29 September lands on a Tuesday again.
In what order are the amounts applied?
Years and months are moved first, on the calendar. Weeks and days are added after that, one day at a time. So "1 month and 10 days" means: go forward one month, then forward ten more days.
What happens at the end of a month?
Months have different lengths, so a day can be missing in the new month. When you add one month to 31 January 2026, there is no 31 February, so the answer is the last day of February, 28 February 2026. In a leap year the answer would be 29 February. The calculator tells you when it has moved the day like this.
Days from today
The start date is set to today when you open the page. To find the date 90 days from now, or the date 6 weeks ago, leave it on today, choose Add or Subtract and enter the amount. The result also shows the day of the week and the day of the year, where 1 January is day 1 and 31 December is day 365 (366 in a leap year).
Days ago, and weeks and months from today
The tables on this page show the date 7, 14, 30, 60, 90 days and more from today, the same counts going back (days ago), and the dates 1 to 52 weeks and 1 to 24 months from today. They are worked out from today’s date on your device. Press Use on a row to put it in the calculator.
Example: 90 days before 1 April 2026 is 1 January 2026, because January, February and March 2026 add up to exactly 90 days.
What day of the week will it be?
The answer always shows the day of the week. A week is 7 days, so adding 7, 14 or 28 days gives the same weekday. Adding 30 days is 4 weeks and 2 days, so the weekday moves forward by 2: a Monday plus 30 days is a Wednesday.
Adding days to a date in Excel and Google Sheets
In a spreadsheet, a date is a number, so you can add days directly: =A1+30 gives the date 30 days after the date in A1. To add months, use =EDATE(A1,3), which adds 3 months and also moves the day to the end of a shorter month, the same as this calculator.
Common uses
- Finding a due date, a deadline or the end of a notice period.
- Working out when a warranty, trial or subscription ends.
- Planning milestones, such as 100 days from a start date.
- Checking what date it was a certain number of weeks or months ago.
