Weekmark

Calendar week · ISO 8601

Week 4, 2025

Monday 20 January – Sunday 26 January 2025

  1. Mon20Jan
  2. Tue21Jan
  3. Wed22Jan
  4. Thu23Jan
  5. Fri24Jan
  6. Sat25Jan
  7. Sun26Jan
ISO week
2025-W04
Copy as
CW4 (20–26 Jan)
Quarter
Q1 2025
Weeks in 2025
52
US week number
4

Week 4 is also written KW 4 (Kalenderwoche) or CW 4. 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 20 Jan to Saturday 25 Jan the same number: week 4.