How many days until the holiday, how many working days left on a notice period, or what is the date 90 days from now? This calculator works out the gap between two dates, and the date you reach by adding or taking away days, weeks, months or years.
How to Use It
The start date begins as today. For the gap between two dates, add an end date. Tick "Count the end date too" if both days should count, for example for a holiday where you are away on the first and last day. For a date in the future or the past, fill in the second section instead.
A Worked Example
One month after 31st January 2026 is Saturday 28th February 2026. The calculator stops at the end of a shorter month rather than running into the next one.
Working Days
Working days here are Monday to Friday. Bank holidays and your own days off are not taken out, so check them against a calendar if the exact number matters.
Questions about Date Calculator
Does the calculator count the end date?
Not unless you tick the box. By default it counts the days from the start date up to the end date, without the end date itself. Tick "Count the end date too" if both days should be included.
Does it leave out bank holidays?
No. Working days means Monday to Friday only. Bank holidays vary and the calculator does not know about them, so take them off yourself if you need an exact figure.
What happens when I add a month to the 31st?
The date stops at the end of the shorter month. One month after 31st January is 28th February, or 29th in a leap year, not a date in March.