Weekmark

Calendar week · ISO 8601

Week 38, 2025

Monday 15 September – Sunday 21 September 2025

  1. Mon15Sep
  2. Tue16Sep
  3. Wed17Sep
  4. Thu18Sep
  5. Fri19Sep
  6. Sat20Sep
  7. Sun21Sep
ISO week
2025-W38
Copy as
CW38 (15–21 Sep)
Quarter
Q3 2025
Weeks in 2025
52
US week number
38

Week 38 is also written KW 38 (Kalenderwoche) or CW 38. ISO weeks start on Monday, and week 1 is the week with the year’s first Thursday. US calendars start weeks on Sunday and count the week with 1 January as week 1, so they give Monday 15 Sep to Saturday 20 Sep the same number: week 38.