Date Difference Calculator
Dates
Counts the last day too: Monday to Friday is 5 days instead of 4.
- Difference
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- Total days
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- End date not counted
Details
How to use
1.
Pick a Start date and an End date - they open at 1 January and today, the Today button in each field fills in the current date, and Reset goes back to that range
2.
Switch on Include end date if the last day should count too, as for a leave request or a multi-day event
3.
Read the Difference in years, months and days beside the Total days, with weeks, business days, total hours and total minutes under Details
Common uses
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Calculating age or years of service
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Counting days remaining until a deadline or event
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Counting business days for project planning or SLA calculations
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Frequently asked questions
Does this account for leap years?
Yes. Days are counted on the real calendar, so a range that spans 29 February includes it: 1 January 2024 to 1 January 2025 is 366 days, and still exactly 1 year. A range that starts on 29 February reaches a whole year on 28 February of a non-leap year.
Is the end date included in the count?
Not by default: the count runs from the earlier date up to, but not including, the later one - so 1 to 2 January is 1 day. Switch on Include end date to count the last day as well. That adds one day to the difference, total days, hours and minutes, and one business day if that last day is a weekday. The dates can be entered in either order; an end date before the start date is flagged, and the gap is still counted.
How are business days calculated?
Business days are Monday to Friday, counted by the same rule: Monday to Friday of the same week is 4 business days, or 5 with the end date included. Public holidays are not subtracted since they vary by country and region.
Is my data sent to a server?
All date calculations run locally in your browser using JavaScript's Date API. No data is transmitted anywhere.
Why does the month count sometimes differ from what I expect?
Months vary in length, so months are counted by stepping through the calendar, not by dividing the days by 30. When the start day does not exist in a later month, that month's last day stands in for it: 31 January to 28 February is 1 month, and 31 January to 1 March is 1 month, 1 day.