How to use the date calculator
To count, pick a start and an end date. The result gives total days, the same span in years, months and days, and how many of those days are weekdays. Turn on Count the end date too when both the first and last day matter, as with a hotel stay counted in days or a notice period.
To move a date, switch to Add or subtract, then choose an amount in days, weeks, months or years.
The formula
Days between dates are counted on the calendar, so leap years are included automatically. Weekdays are Monday to Friday. Public holidays differ by country and are not removed.
When adding months, the day of the month is kept where it exists. One month after 31 January is the last day of February.
Worked example
From 1 January 2026 to 25 December 2026 is 358 days, or 51 weeks and 1 day.
Common questions
Does it include the start and end date?
By default it counts from the start date up to, but not including, the end date. Choose Yes to count both.
How do I count working days?
The weekdays row counts Monday to Friday. Subtract any public holidays that fall in the range.
How many days are in a year?
A normal year has 365 and a leap year 366. Leap years are those divisible by 4, except century years that are not divisible by 400.