Days Between Dates Calculator
Pick two dates and instantly see how many days are between them — in years, months and days, weeks, business days, and hours. Results update as you type.
— days
Counting down to one date instead? Use the days until calculator for a live countdown.
How the days between dates calculator works
This free days between dates calculator — also known as a date duration calculator — works out the exact duration between any two calendar dates. It shows the total number of days first, then the same span as years, months and days, as weeks, as business days (Monday to Friday) and as hours, minutes and seconds. There is no submit button and no page reload: change a date or an option and every number updates straight away.
Include the end date or not?
The biggest source of off-by-one mistakes is whether the last day counts. By default the calculator returns the days between the dates: 1 March to 5 March is 4 days, which is what you want for nights in a hotel or a loan's interest period. If both the first and the last day count — vacation days, a rental period, a festival — tick Include end date and the same span becomes 5 days.
Business days and US federal holidays
Business days are counted as Monday to Friday. For US deadlines — shipping times, contract notice periods, payment terms — you can also subtract the eleven US federal holidays, from New Year's Day and Martin Luther King Jr. Day to Thanksgiving and Christmas. The calculator uses the observed dates: a holiday on a Saturday is taken off on the Friday before, one on a Sunday on the Monday after. Every holiday it subtracts is listed under the result, so you can check it.
A worked example
From 1 January 2027 to 1 March 2027 there are 59 days: 31 in January plus 28 in February. That is 2 months exactly, or 8 weeks and 3 days. Across a leap year the same span is 60 days, because February 2028 has 29 days — the calculator accounts for that automatically.
Frequently Asked Questions
How do I calculate the number of days between two dates?
Enter a start date and an end date. The calculator subtracts them instantly and shows the total number of days, the same span in years, months and days, and in weeks, business days, hours and minutes. No button to press: the result updates as you type.
Does the calculator include the end date?
By default it counts the days between the dates, so from Monday to Tuesday is 1 day. Tick "Include end date" to count both the first and the last day, which is what you want for things like hotel nights versus vacation days, rental periods or event durations: Monday to Tuesday then becomes 2 days.
How are business days counted?
Business days are Monday to Friday. Optionally, US federal holidays (such as Memorial Day, Independence Day, Thanksgiving and Christmas) are subtracted as well, using their observed dates: a holiday on a Saturday is observed on the Friday before, one on a Sunday on the Monday after. The holidays that were subtracted are listed below the result.
Does the date calculator handle leap years?
Yes. Every calculation uses the real calendar, so February 29 in leap years (such as 2028) and months of 28, 30 or 31 days are always counted correctly, however many years apart the two dates are.
Can I share or save a calculation?
Yes. The page address updates with your dates and options as you type, so you can bookmark it or use the Copy link button to share the exact same calculation.
How many weeks are between two dates?
Divide the total number of days by 7. The calculator shows this as full weeks plus the remaining days, for example 100 days is 14 weeks and 2 days.