Date → week number

January 29, 2026: What week number?

Thursday, January 29, 2026ISO Week 52026-W05

ISO Week 5 runs from January 26, 2026 to February 1, 2026.

Mon26JanuaryTue27JanuaryWed28JanuaryThu29JanuaryFri30JanuarySat31JanuarySun1February
← 01-28-202601-30-2026 →

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.

ISO week2026-W05

January 26 – February 1, 2026

MonTueWedThuFriSatSun
Week 1 contains the first Thursday of the year.ISO guide →
US-style weekWeek 5

January 25–31, 2026

SunMonTueWedThuFriSat
Week 1 contains January 1.US-style guide →
ISO weekWeek 5
US-style weekWeek 5
WeekdayThursday
QuarterQ1
Day of year29 / 365
ISO weekday4 / 7

Date context

Thursday, January 29, 2026 is day 29 of 2026 and belongs to ISO Week 5.

This ISO week crosses a month boundary: it starts in January and ends in February.

Distance from today

How long ago was January 29, 2026?

Days200
Full weeks28
Remaining days4

January 29, 2026 is 200 days before today, equal to 28 full weeks and 4 days.