December 2030 Calendar
31 days, 22 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 |
|---|---|---|---|---|---|---|---|
| 48 | 25 | 26 | 27 | 28 | 29 | 30 | 1 |
| 49 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 50 | 9 | 10 | 11 | 12 | 13 | 14 | 15 |
| 51 | 16 | 17 | 18 | 19 | 20 | 21 | 22 |
| 52 | 23 | 24 | 25 | 26 | 27 | 28 | 29 |
| 1 | 30 | 31 | 1 | 2 | 3 | 4 | 5 |
What the week numbers mean
These are ISO 8601 weeks: every week runs Monday to Sunday and belongs to the year that owns its Thursday. It is why 1 January 2027 falls in week 53 of 2026, and why a year has 53 weeks whenever it starts on a Thursday or is a leap year starting on a Wednesday. The US business convention of numbering from 1 January gives different answers, and payroll systems disagree about which one they mean.