Weekmark

Calendar week · ISO 8601

Week 4, 2027

Monday 25 January – Sunday 31 January 2027

  1. Mon25Jan
  2. Tue26Jan
  3. Wed27Jan
  4. Thu28Jan
  5. Fri29Jan
  6. Sat30Jan
  7. Sun31Jan
ISO week
2027-W04
Copy as
CW4 (25–31 Jan)
Quarter
Q1 2027
Weeks in 2027
52
US week number
5

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 25 Jan to Saturday 30 Jan a different number: week 5.