ISO week 2027-W40

Week 40, 2027

Monday, October 4 – Sunday, October 10, 2027

ISO week 40 of 2027 (2027-W40) runs from Monday, October 4, 2027 to Sunday, October 10, 2027.

This week starts 51 weeks from now. The current week is week 42, 2026.

The 7 days of week 40

Dates in week 40, 2027
Day	Date	Day of year	US week	ISO date
Monday	October 4, 2027	277 of 365	41	2027-W40-1
Tuesday	October 5, 2027	278 of 365	41	2027-W40-2
Wednesday	October 6, 2027	279 of 365	41	2027-W40-3
Thursday	October 7, 2027	280 of 365	41	2027-W40-4
Friday	October 8, 2027	281 of 365	41	2027-W40-5
Saturday	October 9, 2027	282 of 365	41	2027-W40-6
Sunday	October 10, 2027	283 of 365	42	2027-W40-7

Week 40 at a glance

ISO code: 2027-W40 (Monday is 2027-W40-1, Sunday is 2027-W40-7)
Month: October
Quarter: Q4 of 2027
Day of year: Days 277–283 of 365
US week number: Monday–Saturday: US week 41; Sunday: US week 42 (Sunday-start weeks, week 1 contains January 1)
Even or odd: Week 40 is an even week
Weeks left: After this week, 12 ISO weeks remain in 2027 (52 weeks in total)
Year progress: By Sunday, 78% of 2027 has passed

Holidays and key dates

There are no US federal holidays, daylight saving time changes or quarter starts in week 40 of 2027.

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 40, 2027

What are the dates of week 40 in 2027?

Week 40 of 2027 starts on Monday, October 4, 2027 and ends on Sunday, October 10, 2027.

What month is week 40 of 2027?

Week 40 falls in October. By the Thursday rule that ISO 8601 uses for years and quarters, it counts as a October week.

How do I get week 40 of 2027 in Excel or Google Sheets?

=ISOWEEKNUM(DATE(2027,10,4)) returns 40. To go the other way, =DATE(2027,1,4)-WEEKDAY(DATE(2027,1,4),2)+1+(40-1)*7 returns the Monday, October 4, 2027.