Date facts
Monday, December 15, 2025
December 15, 2025 is day 349 of 365, in ISO week 51. There are 16 days left in 2025 after this date.
Weekday
Monday
Calendar weekday
Day of year
349
of 365
ISO week
51
Week-year 2025
Days remaining
16
In 2025
Weeks start on Monday and use ISO week numbers. Monday is week 51 of 2025.