Calculate the Days Between Two Dates
Find the exact gap between two dates as years, months and days, as total days and weeks, and as Monday-to-Friday business days. A second mode adds or subtracts days, business days, weeks, months or years from a date.
How to count days between dates
- Choose "Difference between dates" and pick a start and end date. The start date defaults to today.
- Optionally tick "Include times of day" to measure down to the second.
- Tick "Include the end date" if both the first and last day should be counted, as for a booking or leave request.
- To find a future or past date instead, switch to "Add or subtract time" and enter an amount and unit.
Should the end date be included?
By default the tool counts the number of days you move forward from the start to reach the end, so Monday to Friday is 4 days. When you count days of something that occupies both dates, like holiday leave from Monday to Friday, you want 5. Ticking "Include the end date" adds that day to the total and business-day counts. To work out an age from a date of birth, the Age Calculator is a better fit.
Benefits
- Calendar breakdown, total days, weeks, business days and weekend days all at once.
- Optional clock times handle spans that cross midnight correctly.
- Adding months keeps month-end dates sensible: 31 January plus one month gives 28 or 29 February.
Limitations
- Business days skip only Saturdays and Sundays. Public and regional holidays vary too much to include, so subtract them yourself.
- Times are treated as clock times in a single time zone. A daylight-saving change between the two dates is not adjusted for.
Privacy and security
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Frequently asked questions
How are business days counted?
Each Monday to Friday from the start date up to, but not including, the end date is counted, or up to and including it when that option is ticked. Weekends are skipped. Public holidays are not removed automatically.
Why is 31 January to 1 March shown as 1 month and 1 day?
Whole months are counted first. One month after 31 January is the last day of February, and one more day reaches 1 March. Calculators that count 30-day months can give different answers.
Can the end date be before the start date?
Yes. The difference is still shown, labelled as the end date being earlier, so you don't have to swap the fields.