How it works
Days = (end date − start date) ÷ 86,400,000 milliseconds.
A worked example
1 January 2026 to 1 January 2027 spans 365 days.
What to keep in mind
Exclusive elapsed-day count: the same start and end date gives zero. Reversed dates give negative results. Does not exclude weekends or holidays.
How the days between dates are counted
The calculator counts the elapsed days from the start date to the end date. The start date is not counted, so from Monday to Tuesday is 1 day.
Worked examples
From 7 October 2026 to 25 December 2026 is 79 days, or about 11.3 weeks. From 1 January 2026 to 1 January 2027 is 365 days.
Counting both dates
Some situations, such as hotel nights versus days on holiday, count differently. To include both the start and end dates, add one to the result.
Frequently asked questions
How many days until Christmas?
Enter today’s date as the start date and 25 December as the end date.
Does it exclude weekends?
No. It counts all calendar days, including weekends and bank holidays.
Are both dates counted?
No. It measures elapsed days. For an inclusive date count with end on or after start, add one to the result.
Results use the assumptions above. Check critical measurements and dates independently.