Week 51 in 2027
Week 51 of 2027 begins on December 20, 2027 and ends on December 26, 2027. It covers days 354 to 360 of the year and falls in quarter 4.
Weeks until this week: 62
Week 51 of 2027 at a glance
| Starts (Monday) | December 20, 2027 |
|---|---|
| Ends (Sunday) | December 26, 2027 |
| US week (Sunday to Saturday) | 52 (December 19, 2027) |
| Month | December |
| Quarter | Q4 |
| Days of the year | 354–360 |
| Year completed at the end of this week | 98.6% |
| Weeks left in 2027 after this week | 1 |
| Weeks in 2027 | 52 |
| Even or odd week | Odd |
Calendar for December 2027
Download Calendar in printable A4 PDF
(US version) (EU/ISO Version)
All Weeks in 2027:
Past & Future Week Number 51:
US and ISO week numbers
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 52 of 2027. It runs from December 19, 2027 to December 25, 2027.
Even and odd weeks
Week 51 is an odd week. Even and odd week numbers are used for alternating schedules such as shift rotas, school timetables, custody arrangements and waste collection.
Week 51 in other years
| From | To | |
|---|---|---|
| Week 51 in 2025 | December 15, 2025 | December 21, 2025 |
| Week 51 in 2026 | December 14, 2026 | December 20, 2026 |
| Week 51 in 2028 | December 18, 2028 | December 24, 2028 |
| Week 51 in 2029 | December 17, 2029 | December 23, 2029 |
How week numbers are counted
Most of the world numbers weeks according to the ISO 8601 standard. A week starts on Monday, and week 1 is the week that contains the first Thursday of the year, which is always the week that contains 4 January.
Week 1 of 2027 began on January 4, 2027. 2027 has 52 ISO weeks.
Because of this rule, the first days of January can belong to the last week of the previous year, and the last days of December can belong to week 1 of the next year.
In the United States, weeks usually start on Sunday and week 1 is the week that contains 1 January, so the US week number can differ from the ISO week number.
Find the week number of a date
Frequently Asked Questions (FAQ)
When does week 51 of 2027 start and end?
Week 51 of 2027 starts on December 20, 2027 and ends on December 26, 2027 (ISO 8601, Monday to Sunday).
Which month is week 51 of 2027 in?
Week 51 of 2027 is in December.
What dates are in week 51 of 2027?
December 20, 2027, December 21, 2027, December 22, 2027, December 23, 2027, December 24, 2027, December 25, 2027, and December 26, 2027
How many weeks does 2027 have?
2027 has 52 ISO weeks.
Is week 51 an even or odd week?
Week 51 is an odd week.
What is the US week number for this week?
In the US system, where weeks start on Sunday and week 1 is the week that contains 1 January, this is week 52 of 2027. It runs from December 19, 2027 to December 25, 2027.