January 19–25, 2026
MonTueWedThuFriSatSun
Week 1 contains the first Thursday of the year.ISO guide →Date → week number
January 23, 2026: What week number?
Friday, January 23, 2026ISO Week 42026-W04
ISO Week 4 runs from January 19, 2026 to January 25, 2026.
ISO vs US-style week numbers
The same date can have different week numbers
ISO weeks start on Monday. The simplified US-style system starts on Sunday and counts the week containing January 1 as Week 1.
January 18–24, 2026
SunMonTueWedThuFriSat
Week 1 contains January 1.US-style guide →ISO weekWeek 4
US-style weekWeek 4
WeekdayFriday
QuarterQ1
Day of year23 / 365
ISO weekday5 / 7
January 2026
Date context
Friday, January 23, 2026 is day 23 of 2026 and belongs to ISO Week 4.
The entire ISO Week 4 falls within January.
Distance from today
How long ago was January 23, 2026?
Days206
Full weeks29
Remaining days3
January 23, 2026 is 206 days before today, equal to 29 full weeks and 3 days.