Date Calculator
Find out how many days are between two dates, or work out the date a number of days, weeks, months or years before or after another date. Leap years and different month lengths are handled for you.
Years and months are counted on the calendar, not by dividing days, because months have 28 to 31 days. From 31 January, one month later is the last day of February. Leap years are handled automatically.
- Total days
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- Years, months and days
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- Weeks
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- Whole months
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How to Use the Date Calculator
- Choose a calculation type: days between two dates, or add or subtract from a date.
- For the difference, pick a start date and an end date. Use the Today buttons for the current date, and tick Include the end date if both the first and last day should count, for example for a holiday or a hire period.
- To add or subtract, choose the start date, Add or Subtract, the amount and the unit (days, weeks, months or years).
- Read the result, then copy or save it.
Examples
Days between two dates
- Input
- 1 January 2026 → 25 December 2026
- Output
- Total days: 358 Weeks: 51 weeks, 1 day Years, months and days: 11 months, 24 days
Add days to a date
- Input
- 1 March 2026 + 90 days
- Output
- Saturday, May 30, 2026
Across a leap day
- Input
- 1 February 2028 → 1 March 2028
- Output
- Total days: 29 (2028 is a leap year)
About the Date Calculator
Date calculations come up all the time: counting down to a deadline or event, working out notice periods and contract terms, checking how long a project or trip lasts, or finding the date 30, 60 or 90 days after an invoice.
The day count is exact. Dates are treated as whole calendar days with no time of day, so time zones and daylight saving changes cannot shift the result by one. Leap years follow the Gregorian calendar: years divisible by 4 are leap years, except century years that are not divisible by 400, so 2000 was a leap year and 2100 will not be.
Months and years are counted on the calendar rather than by dividing the number of days, because months have between 28 and 31 days. The calculator counts how many whole months fit between the two dates, then the days left over. When the target month is shorter, it uses the last day of that month, so one month after 31 January is 28 February, or 29 February in a leap year. Other calculators can treat these month-end cases differently.
By default the end date is not counted, so Monday to Tuesday is 1 day. Tick Include the end date to count both the first and the last day. The calculation runs in your browser with JavaScript, and this tool does not send what you enter to a Usevanta server.
Frequently Asked Questions
How do I count the days between two dates?
Choose Days between two dates, enter both dates and read Total days. From Monday to Friday is 4 days, or 5 if you tick Include the end date.
Does the calculator include the end date?
Not by default. This matches how most people count elapsed time, such as the number of nights in a hotel stay. Tick Include the end date when both days count, such as for a 5-day event from Monday to Friday.
How are leap years handled?
Automatically. February has 29 days in leap years, so 1 February to 1 March 2028 is 29 days, while the same dates in 2027 are 28 days apart.
Why is the month count not just days divided by 30?
Because months are not all the same length. The calculator counts real calendar months, so 15 January to 15 March is exactly 2 months even though it is 59 days, or 60 in a leap year.
What date is 90 days from today?
Choose Add or subtract from a date, press Today, keep Add selected, enter 90 and keep Days as the unit. The result shows the exact date and day of the week.
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