Week 21 of the year
When is week 21? The exact Monday–Sunday dates of ISO week 21 for every year from 2024 to 2032.
Week 21 of 2026 runs from Monday, May 18, 2026 to Sunday, May 24, 2026 (May). Week 21 of 2026 has already passed (8 weeks ago). ISO week code: 2026-W21.
Week 21 dates by year
| Year | Week 21 starts (Mon) | Week 21 ends (Sun) | Month |
|---|---|---|---|
| 2024 | Monday, May 20, 2024 | Sunday, May 26, 2024 | May |
| 2025 | Monday, May 19, 2025 | Sunday, May 25, 2025 | May |
| 2026 | Monday, May 18, 2026 | Sunday, May 24, 2026 | May |
| 2027 | Monday, May 24, 2027 | Sunday, May 30, 2027 | May |
| 2028 | Monday, May 22, 2028 | Sunday, May 28, 2028 | May |
| 2029 | Monday, May 21, 2029 | Sunday, May 27, 2029 | May |
| 2030 | Monday, May 20, 2030 | Sunday, May 26, 2030 | May |
| 2031 | Monday, May 19, 2031 | Sunday, May 25, 2031 | May |
| 2032 | Monday, May 17, 2032 | Sunday, May 23, 2032 | May |
All weeks
Frequently asked questions
What month is week 21 in?
Week 21 typically falls in May. The exact dates shift by up to a few days from year to year because week 1 is anchored to January 4, not January 1.
How do I write week 21 as a week code?
The ISO code is the year plus W21 — for example 2026-W21, short form 26W21, or YYWW date code 2621. See week number formats.
Are these dates the same in every country?
Yes for ISO 8601 (Monday-start) numbering, which is what this table shows. US Sunday-start calendars can label the same days with a number one higher — see week start conventions.