ISO week 2026-W18

Week 18, 2026

Monday, April 27 – Sunday, May 3, 2026

ISO week 18 of 2026 (2026-W18) runs from Monday, April 27, 2026 to Sunday, May 3, 2026.

This week ended 24 weeks ago. The current week is week 42, 2026.

The 7 days of week 18

Dates in week 18, 2026
Day	Date	Day of year	US week	ISO date
Monday	April 27, 2026	117 of 365	18	2026-W18-1
Tuesday	April 28, 2026	118 of 365	18	2026-W18-2
Wednesday	April 29, 2026	119 of 365	18	2026-W18-3
Thursday	April 30, 2026	120 of 365	18	2026-W18-4
Friday	May 1, 2026	121 of 365	18	2026-W18-5
Saturday	May 2, 2026	122 of 365	18	2026-W18-6
Sunday	May 3, 2026	123 of 365	19	2026-W18-7

Week 18 at a glance

ISO code: 2026-W18 (Monday is 2026-W18-1, Sunday is 2026-W18-7)
Month: April and May
Quarter: Q2 of 2026
Day of year: Days 117–123 of 365
US week number: Monday–Saturday: US week 18; Sunday: US week 19 (Sunday-start weeks, week 1 contains January 1)
Even or odd: Week 18 is an even week
Weeks left: After this week, 35 ISO weeks remain in 2026 (53 weeks in total)
Year progress: By Sunday, 34% of 2026 has passed

Holidays and key dates

There are no US federal holidays, daylight saving time changes or quarter starts in week 18 of 2026.

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 18, 2026

What are the dates of week 18 in 2026?

Week 18 of 2026 starts on Monday, April 27, 2026 and ends on Sunday, May 3, 2026.

What month is week 18 of 2026?

Week 18 falls in April and May. By the Thursday rule that ISO 8601 uses for years and quarters, it counts as a April week.

How do I get week 18 of 2026 in Excel or Google Sheets?

=ISOWEEKNUM(DATE(2026,4,27)) returns 18. To go the other way, =DATE(2026,1,4)-WEEKDAY(DATE(2026,1,4),2)+1+(18-1)*7 returns the Monday, April 27, 2026.