Date to Week Number
Get the ISO week number for any date
ISO Week Number
W05
2026-W05
Day of Week
Friday
Day 5 of 7
Week Range
Mon - Sun
Jan 26, 2026
Weeks in Year
53
ISO year 2026
Week Boundaries
Week starts:Mon, Jan 26, 2026
Week ends:Sun, Feb 1, 2026
Week Number to Date Range
Find the date range for a specific week
Range: 1900 - 2100
Range: 1 - 53
2026-W05
Mon, Jan 26, 2026 - Sun, Feb 1, 2026
Days in Week 5
MonJan 26, 2026
TueJan 27, 2026
WedJan 28, 2026
ThuJan 29, 2026
FriJan 30, 2026
SatJan 31, 2026
SunFeb 1, 2026
Current Week
We are currently in
Week 5 of 2026
ISO notation: 2026-W05
About ISO Week Numbers
- ISO weeks start on Monday and end on Sunday
- Week 1 is the week containing the first Thursday of the year
- A year can have 52 or 53 weeks
- December 31 might be in week 1 of the next year
- January 1 might be in week 52 or 53 of the previous year