Count the days between two dates, or find the date a number of days, weeks or months from another date.
Dates use the Gregorian calendar and your device's date. Deadlines in law or contracts can have their own rules for counting days, so check those. Terms of use.
How the dates are counted
The days between two dates is the number of midnights from the first to the second. Turning on "Include the end date" adds one, so a period that starts and ends on the same day counts as 1 day. Months are counted as whole calendar months from the start date, then the days left over.
When you add months or years, the day of the month stays the same where it can. If the new month is too short, the answer is that month's last day.
Example. From Thu 1 January 2026 to Fri 25 December 2026 is 358 days, which is 51 weeks and 1 day, or 11 months and 24 days. One month after 31 January 2026 is Sat 28 February 2026.
Questions
Does the count include the start date and end date?
By default it counts the days from the start date to the end date, the way you would count nights: Monday to Friday is 4 days. Turn on "Include the end date" to count both days, so Monday to Friday is 5 days.
What happens when I add a month to 31 January?
There is no 31 February, so the answer is the last day of February: 28 February, or 29 February in a leap year. The same applies to any month that is shorter than the day you start on.
How do I count working days instead?
Use the working days calculator. It leaves out weekends and Irish public holidays, including St Brigid's Day and the days off in lieu when a holiday falls on a weekend.
How do I count back from a date?
Choose "Add or subtract", then enter a minus number. Minus 30 days from 10 October is 10 September.
How many days are there in a year?
A common year has 365 days and a leap year has 366. A year is a leap year if it divides by 4, except century years, which must divide by 400. 2028 is the next leap year.
