Week 51 of 2026: Dates
Week 51 of 2026 starts on Monday, December 14, 2026 and ends on Sunday, December 20, 2026. It falls in December, in the fourth quarter of 2026.
The days of week 51, 2026
| Day | Date | Day of year | US federal holiday |
|---|---|---|---|
| Monday | December 14, 2026 | Day 348 | |
| Tuesday | December 15, 2026 | Day 349 | |
| Wednesday | December 16, 2026 | Day 350 | |
| Thursday | December 17, 2026 | Day 351 | |
| Friday | December 18, 2026 | Day 352 | |
| Saturday | December 19, 2026 | Day 353 | |
| Sunday | December 20, 2026 | Day 354 |
Other days in this week: Victory Day (Bangladesh).
ISO and US week numbers
Week 51 covers days 348 to 354 of 2026. US calendars start the week a day earlier, on Sunday, December 13. On that count the same Monday is in week 51 of 2026, so here the two numbers match. To check it in Excel or Google Sheets, =ISOWEEKNUM(DATE(2026,12,14)) returns 51 and =WEEKNUM(DATE(2026,12,14)) returns 51.
Week 51 by year
| Year | Monday | Sunday |
|---|---|---|
| 2026 | December 14, 2026 | December 20, 2026 |
| 2027 | December 20, 2027 | December 26, 2027 |
| 2028 | December 18, 2028 | December 24, 2028 |
| 2029 | December 17, 2029 | December 23, 2029 |
| 2030 | December 16, 2030 | December 22, 2030 |
| 2031 | December 15, 2031 | December 21, 2031 |
This page shows the next week 51 that has not ended yet. ISO weeks start on Monday, and week 1 contains the year's first Thursday.
Week 51 questions
When does week 51 of 2026 start?
On Monday, December 14, 2026. It ends on Sunday, December 20, 2026, seven days later.
Does every year have a week 51?
Yes. Every ISO year has weeks 1 to 52, and only some have a week 53.
Related pages
Cite this page
APA: ClockTotals. (2026, October 27). Week 51 of 2026: Dates. https://clocktotals.com/week-number/51/
MLA: “Week 51 of 2026: Dates.” ClockTotals, 27 Oct. 2026, clocktotals.com/week-number/51/.
Link (HTML): <a href="https://clocktotals.com/week-number/51/">Week 51 of 2026: Dates</a>