What Day of the Week Is December 21?
December 21, 2026 falls on a Monday.
It is day 355 of 2026, and 10 days of the year come after it. The date sits in ISO week 52 and in the fourth quarter, October to December. The December solstice falls on this date in 2026, so winter begins in the Northern Hemisphere. The Moon is a waxing gibbous that day, and the next full moon is on Wednesday, December 23, 2026. It is not a US federal holiday.
December 21 from 2025 to 2028
The same date in four years, side by side. Moon phases use US Eastern dates.
| Fact | 2025 | 2026 | 2027 | 2028 |
|---|---|---|---|---|
| Day of the week | Sunday | Monday | Tuesday | Thursday |
| Day of the year | 355 of 365 | 355 of 365 | 355 of 365 | 356 of 366 |
| Days left in the year | 10 | 10 | 10 | 10 |
| ISO week | 51 | 52 | 51 | 51 |
| Quarter | Q4 | Q4 | Q4 | Q4 |
| Season (north) | First day of winter | First day of winter | First day of winter | First day of winter |
| Moon (US Eastern) | Waxing crescent | Waxing gibbous | Waning crescent | Waxing crescent |
| US federal holiday | No | No | No | No |
| Other holidays | – | – | – | – |
Holidays on December 21
None of the 245 holidays and observances on this site is fixed to December 21.
Holidays that move with the calendar land on December 21 in some years from 2026 to 2035.
| Holiday or observance | Years on December 21 |
|---|---|
| Hanukkah | 2030 |
Born on December 21
In most horoscope tables, December 21 falls under Sagittarius, the sign that runs from November 22 to December 21. The Sun can move into Capricorn a day early in some years, so a few tables list December 21 under Capricorn.
The birthstone for December is the turquoise, and the American Gem Society also lists tanzanite, zircon and blue topaz.
December 21 every year from 1950 to 2049
Find the decade on the left, then the last digit of the year across the top. A baby born on December 21, 1990 arrived on a Friday, and one born on December 21, 2000 on a Thursday. Weekends are shaded.
| Years | …0 | …1 | …2 | …3 | …4 | …5 | …6 | …7 | …8 | …9 |
|---|---|---|---|---|---|---|---|---|---|---|
| 1950s | Thu | Fri | Sun | Mon | Tue | Wed | Fri | Sat | Sun | Mon |
| 1960s | Wed | Thu | Fri | Sat | Mon | Tue | Wed | Thu | Sat | Sun |
| 1970s | Mon | Tue | Thu | Fri | Sat | Sun | Tue | Wed | Thu | Fri |
| 1980s | Sun | Mon | Tue | Wed | Fri | Sat | Sun | Mon | Wed | Thu |
| 1990s | Fri | Sat | Mon | Tue | Wed | Thu | Sat | Sun | Mon | Tue |
| 2000s | Thu | Fri | Sat | Sun | Tue | Wed | Thu | Fri | Sun | Mon |
| 2010s | Tue | Wed | Fri | Sat | Sun | Mon | Wed | Thu | Fri | Sat |
| 2020s | Mon | Tue | Wed | Thu | Sat | Sun | Mon | Tue | Thu | Fri |
| 2030s | Sat | Sun | Tue | Wed | Thu | Fri | Sun | Mon | Tue | Wed |
| 2040s | Fri | Sat | Sun | Mon | Wed | Thu | Fri | Sat | Mon | Tue |
When December 21 is on the same weekday again
After 2026, December 21 is next a Monday in 2037. The next weekend December 21 is in 2030, on a Saturday.
| Day of the week | Next year after 2026 |
|---|---|
| Monday | 2037 |
| Tuesday | 2027 |
| Wednesday | 2033 |
| Thursday | 2028 |
| Friday | 2029 |
| Saturday | 2030 |
| Sunday | 2031 |
December 21 by year
| Year | Day of the week | Weekend or weekday |
|---|---|---|
| 2023 | Thursday | Weekday |
| 2024 | Saturday | Weekend |
| 2025 | Sunday | Weekend |
| 2026 | Monday | Weekday |
| 2027 | Tuesday | Weekday |
| 2028 | Thursday | Weekday |
| 2029 | Friday | Weekday |
| 2030 | Saturday | Weekend |
| 2031 | Sunday | Weekend |
| 2032 | Tuesday | Weekday |
| 2033 | Wednesday | Weekday |
| 2034 | Thursday | Weekday |
Why the weekday changes
A common year is 365 days, one day more than 52 weeks. So December 21 moves on one weekday each year: Monday in 2026, Tuesday in 2027. The jump is two days when February 29 comes in between, so December 21, 2028 is a Thursday, two on from 2027's Tuesday. Between 1901 and 2099, the whole pattern repeats every 28 years.
More about December 21 on this site
December 21 questions
What day of the week is December 21, 2026?
December 21, 2026 is a Monday. It is day 355 of the year and falls in ISO week 52.
Is December 21 a holiday?
None of the holidays on this site is fixed to December 21. December 21, 2026 is not a US federal holiday. Some years it is Hanukkah instead, as in 2030.
Cite this page
APA: ClockTotals. (2026, October 31). What Day of the Week Is December 21? https://clocktotals.com/what-day-is/december-21/
MLA: “What Day of the Week Is December 21?” ClockTotals, 31 Oct. 2026, clocktotals.com/what-day-is/december-21/.
Link (HTML): <a href="https://clocktotals.com/what-day-is/december-21/">What Day of the Week Is December 21?</a>