Date Calculations Made Simple
Whether you're counting down to an event, working out a notice period, checking a deadline or planning a project, date maths comes up all the time. Months of different lengths and leap years make it easy to get wrong by hand. This calculator does two jobs: it counts the time between two dates, and it adds or subtracts time from a date.
Counting days between two dates
Choose a start and end date. The calculator shows the duration in total days, in years, months and days, and in weeks. It also counts working days (Monday to Friday) and weekend days, which is useful for project planning and notice periods.
Should the end date be included?
By default, the calculator counts the days between the dates, so 1 January to 2 January is 1 day. If you're counting days of an event or a hotel stay where both the first and last day count, choose "Yes" to include the end date and add one day.
Adding or subtracting time
Switch to "Add or subtract" to find the date a certain number of days, weeks, months or years from your start date. For example:
- What date is 90 days from today? (a common payment or visa window)
- What was the date 6 months ago?
- When does a 2-year contract end?
When adding months, if the start day doesn't exist in the result month, the calculator uses the last day of that month. For example, 31 January + 1 month = 28 or 29 February.
A note on working days
Working days here means Monday to Friday. Public holidays differ by country and region and are not removed, so subtract any holidays that apply to you. Some countries also have a different weekend, such as Friday and Saturday.
Want to know your exact age? Try the age calculator.