ISO week 2027-W51

Week 51, 2027

Monday, December 20 – Sunday, December 26, 2027

ISO week 51 of 2027 (2027-W51) runs from Monday, December 20, 2027 to Sunday, December 26, 2027.

This week starts 62 weeks from now. The current week is week 42, 2026.

The 7 days of week 51

Dates in week 51, 2027
Day	Date	Day of year	US week	ISO date
Monday	December 20, 2027	354 of 365	52	2027-W51-1
Tuesday	December 21, 2027	355 of 365	52	2027-W51-2
Wednesday	December 22, 2027	356 of 365	52	2027-W51-3
Thursday	December 23, 2027	357 of 365	52	2027-W51-4
Friday	December 24, 2027	358 of 365	52	2027-W51-5
Saturday	December 25, 2027	359 of 365	52	2027-W51-6
Sunday	December 26, 2027	360 of 365	53	2027-W51-7

Week 51 at a glance

ISO code: 2027-W51 (Monday is 2027-W51-1, Sunday is 2027-W51-7)
Month: December
Quarter: Q4 of 2027
Day of year: Days 354–360 of 365
US week number: Monday–Saturday: US week 52; Sunday: US week 53 (Sunday-start weeks, week 1 contains January 1)
Even or odd: Week 51 is an odd week
Weeks left: After this week, 1 ISO week remain in 2027 (52 weeks in total)
Year progress: By Sunday, 99% of 2027 has passed

Holidays and key dates

Friday, December 24: Christmas Day (observed) – US federal holiday (December 25 falls on a Saturday)
Saturday, December 25: Christmas Day – US federal holiday

Week numbers follow ISO 8601: weeks start on Monday and week 1 contains the first Thursday of the year. US weeks start on Sunday, with week 1 containing January 1.

Questions about week 51, 2027

What are the dates of week 51 in 2027?

Week 51 of 2027 starts on Monday, December 20, 2027 and ends on Sunday, December 26, 2027.

What month is week 51 of 2027?

Week 51 falls in December. By the Thursday rule that ISO 8601 uses for years and quarters, it counts as a December week.

How do I get week 51 of 2027 in Excel or Google Sheets?

=ISOWEEKNUM(DATE(2027,12,20)) returns 51. To go the other way, =DATE(2027,1,4)-WEEKDAY(DATE(2027,1,4),2)+1+(51-1)*7 returns the Monday, December 20, 2027.