December 21, 2026 falls on a Monday
December 21, 2026 is a Monday. It is 89 days from today, September 23, 2026. The date is day 355 of 365 in 2026, it sits in ISO week 52, and it is the 21st of a 31-day month with 10 days after it. December 21 is also December solstice, a astronomical.
What day of the week is December 21?
In 2026 it is a Monday. The weekday is not a property of the date itself, it is a property of the date in a given year, so the honest answer always names the year. A common year is 365 days, which is 52 weeks plus one spare day, so a fixed date moves forward one weekday from one year to the next. A leap year inserts a second spare day, so the step is two whenever 29 February falls inside the gap. That is why December 21 works its way around the week rather than repeating on a tidy schedule.
December 21 in the next few years
| Year | Weekday | Day of year | ISO week | Leap year |
|---|---|---|---|---|
| 2026 | Monday | 355 | 52 | no |
| 2027 | Tuesday | 355 | 51 | no |
| 2028 | Thursday | 356 | 51 | yes |
| 2029 | Friday | 355 | 51 | no |
| 2030 | Saturday | 355 | 51 | no |
| 2031 | Sunday | 355 | 51 | no |
| 2032 | Tuesday | 356 | 52 | yes |
| 2033 | Wednesday | 355 | 51 | no |
Between 2026 and 2027 the weekday moves from Monday to Tuesday, a step of 1. The day-of-year column also moves: December 21 is day 355 in a common year and day 356 in a leap year, because it sits after 29 February.
How often does December 21 fall at a weekend?
Counting the 28 occurrences from 2026 to 2053, December 21 lands on a Saturday 4 times and on a Sunday 4 times, so 8 of those 28 years put it at a weekend. Over a full 28-year stretch the Gregorian calendar repeats itself, and a fixed date visits each weekday four times, so the long-run answer is two weekend years in every seven.
Where December 21 sits in the calendar
December 21 is the 21st day of December, a month of 31 days in 2026, leaving 10 days of the month after it. Measured from 1 January it is 354 days into the year, and 10 days remain to 31 December, which puts it 97.3% of the way through 2026. In December 2026 the other Mondays are the 7th, 14th, 28th, because weekdays repeat every seven days inside a month just as they do across one.
What else happens around December 21?
| Date | Occasion | Type | Days from December 21 |
|---|---|---|---|
| December 21 | December solstice | astronomical | same day |
| December 24 | Christmas Eve | observance | 3 after |
| December 25 | Christmas Day | federal holiday | 4 after |
How far away is December 21?
The next December 21 is Monday, December 21, 2026, 89 days from today. That is 12 whole weeks and 5 days, or 12.7 weeks written as a decimal. To count towards it second by second, use the date calculator.
Questions
- What day of the week is December 21, 2026?
- A Monday. It is day 355 of 365 and falls in ISO week 52.
- What day of the week is December 21 next year?
- In 2027 it is a Tuesday.
- What number day of the year is December 21?
- Day 355 in a common year and day 356 in a leap year. See day 355 for more.
- Which week of the year is December 21 in?
- ISO week 52 in 2026. The week 52 page lists every date in it.
Nearby dates
The 21st of other months
All 366 dates · Week 52 · Day 355 of the year · Event countdowns · When is it? · Date calculator