How the dates are counted
By default the calculator counts the days from the start date up to the end date, without counting the end date itself, so 1 January to 2 January is 1 day. Choose to include the end date if you want both dates to count, for example for the length of a holiday or a notice period.
Years and months are counted in whole calendar months from the start date, with the days left over shown at the end. Weekdays are Monday to Friday; bank and public holidays aren't taken off.
If you enter the end date before the start date, the calculator swaps them.
Worked example
From 1 January 2026 to 25 December 2026 is 358 days. That's 51 weeks and 1 day, or 11 months and 24 days, and includes 256 weekdays.
If you include the end date, it's 359 days: 51 weeks and 2 days, or 11 months and 25 days, with 257 weekdays.
Inputs for the date calculator
Start date
The first date in the period.
End date
The last date in the period. If it's earlier than the start date, the two are swapped.
Count the end date as a day?
Choose 'No' to count the days between the dates. Choose 'Yes' to add the end date as an extra day, so both the first and last days count.
CALCULATOR QUESTIONS
Date calculator questions
How many days until Christmas?
Enter today's date as the start date and 25 December as the end date. From 1 January 2026, it's 358 days.
Should I include the end date?
Include it when both the first and last days count, such as days of leave or the length of an event. Leave it out to count the time between two dates, such as how many days until a deadline.
Does the weekday count include bank holidays?
Yes. It counts every Monday to Friday, so take off any bank or public holidays yourself to get working days.
Does it handle leap years?
Yes. The calculator uses the real calendar, so 29 February is counted in leap years.