ISO week 2027-W52

Week 52, 2027

Monday, December 27, 2027 – Sunday, January 2, 2028

ISO week 52 of 2027 (2027-W52) runs from Monday, December 27, 2027 to Sunday, January 2, 2028.

This week starts 63 weeks from now. The current week is week 42, 2026.

The 7 days of week 52

Dates in week 52, 2027
Day	Date	Day of year	US week	ISO date
Monday	December 27, 2027	361 of 365	53	2027-W52-1
Tuesday	December 28, 2027	362 of 365	53	2027-W52-2
Wednesday	December 29, 2027	363 of 365	53	2027-W52-3
Thursday	December 30, 2027	364 of 365	53	2027-W52-4
Friday	December 31, 2027	365 of 365	53	2027-W52-5
Saturday	January 1, 2028	1 of 366	1	2027-W52-6
Sunday	January 2, 2028	2 of 366	2	2027-W52-7

Week 52 at a glance

ISO code: 2027-W52 (Monday is 2027-W52-1, Sunday is 2027-W52-7)
Month: December and January
Quarter: Q4 by the ISO rule (its Thursday, December 30, is in Q4); the calendar dates span Q4 and Q1
Day of year: December 27, 2027 is day 361 of 2027; January 2, 2028 is day 2 of 2028
US week number: Monday–Friday: US week 53 of 2027; Saturday: US week 1 of 2028; Sunday: US week 2 of 2028 (Sunday-start weeks, week 1 contains January 1)
Even or odd: Week 52 is an even week
Weeks left: This is the last ISO week of 2027
Year progress: This week spans New Year

Holidays and key dates

Friday, December 31: New Year's Day (observed) – US federal holiday (January 1 falls on a Saturday)
Saturday, January 1: New Year's Day – US federal holiday

End of the ISO year

2027 has 52 ISO weeks, so week 52 is the final week. The next Monday, Monday, January 3, 2028, starts week 1 of 2028.

January 1–2, 2028 still belong to ISO year 2027, so dates in this week can show different calendar and ISO years.

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 52, 2027

What are the dates of week 52 in 2027?

Week 52 of 2027 starts on Monday, December 27, 2027 and ends on Sunday, January 2, 2028.

What month is week 52 of 2027?

Week 52 falls in December and January. By the Thursday rule that ISO 8601 uses for years and quarters, it counts as a December week.

How do I get week 52 of 2027 in Excel or Google Sheets?

=ISOWEEKNUM(DATE(2027,12,27)) returns 52. To go the other way, =DATE(2027,1,4)-WEEKDAY(DATE(2027,1,4),2)+1+(52-1)*7 returns the Monday, December 27, 2027.