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.
A common question
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.