ISO week calendar

Week 25 2026

ISO week 25 of 2026 runs from Monday, June 15, 2026 to Sunday, June 21, 2026.

Date Time Encyclopedia answer, with calculation details and assumptions below.

ISO weeks start on Monday and end on Sunday. Week 1 is the week containing the first Thursday of the ISO week-numbering year.

Snapshot

Week 25 2026

ISO week 25 of 2026 runs from Monday, June 15, 2026 to Sunday, June 21, 2026.

ISO weeks start on Monday and end on Sunday. Week 1 is the week containing the first Thursday of the ISO week-numbering year.

Week starts
Monday, June 15, 2026
Week ends
Sunday, June 21, 2026
ISO year
2026
Weeks in ISO year
53

ISO week 25, 2026

  1. MonJun 15, 2026Week start
  2. TueJun 16, 20262026-W25
  3. WedJun 17, 20262026-W25
  4. ThuJun 18, 20262026-W25
  5. FriJun 19, 20262026-W25
  6. SatJun 20, 20262026-W25
  7. SunJun 21, 2026Week end

Method

Find the Monday of ISO week 1, then add seven days for each week after it.

ISO week context

Week 25 2026 uses the ISO week-date system: weeks start Monday, end Sunday, and week 1 is tied to the first Thursday of the ISO year.

Compare nearby ISO weeks

Adjacent week pages help verify handoffs between reporting periods, sprints, payroll periods, and weekly plans.

FAQ

When does this ISO week start?

Week 25 of 2026 starts on Monday, June 15, 2026.

When does this ISO week end?

Week 25 of 2026 ends on Sunday, June 21, 2026.