December 2025 Calendar
December 2025 has 31 days, 23 of them working days once Saturdays and Sundays are removed. Week numbers follow ISO 8601, which gives a week to the year that owns its Thursday — that is why 1 January can fall in week 53 of the year before. Marked days: Christmas Day, New Year's Eve. The ones that move are placed by a rule, printed beside each date.
Holiday rules and week numbering checked · How we check
31 days, 23 of them working days. The number down the left is the ISO week; public holidays are not deducted, because which ones apply depends on where you are.
| wk | Mo | Tu | We | Th | Fr | Sa | Su |
|---|---|---|---|---|---|---|---|
| 49 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 50 | 8 | 9 | 10 | 11 | 12 | 13 | 14 |
| 51 | 15 | 16 | 17 | 18 | 19 | 20 | 21 |
| 52 | 22 | 23 | 24 | 25 | 26 | 27 | 28 |
| 1 | 29 | 30 | 31 | 1 | 2 | 3 | 4 |
How many of each day
Every month holds four of every weekday and then two or three days over. Which weekdays get the extra one is the only thing separating this month from any other of the same length — and it is what decides a five-payday month for anyone paid weekly.
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
| 5 | 5 | 5 | 4 | 4 | 4 | 4 |
- Monday, Tuesday, Wednesday come round five times; every other day four.
- It opens on a Monday and closes on a Wednesday, covering ISO weeks 49 to 1 in quarter 4.
- Day 335 to day 365 of 2025, leaving 0 days in the year after it.
- The identical grid returns in 2008, 2014, 2031 and 2036 — same starting weekday, same length, so a wall calendar from one of those years hangs again unchanged.
Marked days in December 2025
Underlined in the grid above. Each one links to the count of days until it and the rule that places it, because half of these are not on a fixed date at all.
Christmas Day Thu, December 25, 2025
New Year's Eve Wed, December 31, 2025
Which day does the week start on?
Laid out Monday first, as ISO weeks are.
What do the week numbers mean?
The number down the left of each row is the ISO 8601 week, which runs Monday to Sunday and belongs to the year that owns its Thursday. December 2025 covers weeks 49 to 1. Every week of 2025, numbered.
Other months of 2025
Other years
Questions people actually ask
- How many days does December 2025 have?
- 31, of which 23 are working days once Saturdays and Sundays are removed and 8 are weekend days. Public holidays are not deducted from that figure, because which ones apply depends on where you are — Christmas Day, New Year's Eve fall in this month.
- How many Mondays, Tuesdays, Wednesdays are in December 2025?
- Five of each — Monday, Tuesday, Wednesday come round a fifth time where every other weekday comes four. That is what separates this month from any other of the same length, and for anyone paid weekly it is the difference between four cheques and five.
- What week number is December 2025?
- It spans ISO weeks 49 to 1. An ISO week runs Monday to Sunday and belongs to the year that owns its Thursday, which is why the first days of January can carry week 53 of the year before. The US business convention of numbering from 1 January gives different answers, and payroll systems disagree about which one they mean.
- What day of the week does December 2025 start on?
- A Monday, and it ends on a Wednesday. It runs from day 335 to day 365 of the year, leaving 0 days after it.