Date-to-date calculator

Days between dates

Count the distance between two Gregorian calendar dates. Weekdays mean Monday through Friday and do not exclude holidays.

Excluding the start date

17,427 days

From Sunday, December 17, 1978 to Thursday, September 3, 2026.

Monday–Friday weekdays12,449
Weeks and days2,489w 4d
Calendar span47 years, 8 months, 17 days

Standard mode excludes the earlier endpoint and includes the later endpoint. Reversed inputs keep the same absolute counts and are identified above.