Week numbers by year
Complete ISO 8601 week number charts — every week of every year with its Monday–Sunday dates. It is currently week 29 of 2026.
Choose a year
Week numbers 2024
52 weeks · week 1 starts Jan 1, 2024
Week numbers 2025
52 weeks · week 1 starts Dec 30, 2024
Week numbers 2026
53 weeks · week 1 starts Dec 29, 2025 · 53-week year
Week numbers 2027
52 weeks · week 1 starts Jan 4, 2027
Week numbers 2028
52 weeks · week 1 starts Jan 3, 2028
Week numbers 2029
52 weeks · week 1 starts Jan 1, 2029
Week numbers 2030
52 weeks · week 1 starts Dec 31, 2029
Week numbers 2031
52 weeks · week 1 starts Dec 30, 2030
Week numbers 2032
53 weeks · week 1 starts Dec 29, 2031 · 53-week year
Or jump to a specific week
Each week has its own page showing its dates in every year — useful when someone says "week 32" and you need to know exactly when that is.
About these charts
All charts use the ISO 8601 week date standard: weeks start on Monday and week 1 is the week containing January 4. That is the numbering used by most planners, project tools, and businesses in Europe, and by international logistics everywhere. If your organisation runs a 4-4-5 fiscal calendar or a Sunday-start week, your internal week numbers may differ from these by design.
Frequently asked questions
Which years have 53 weeks?
Between 2020 and 2040 the ISO years with 53 weeks are 2020, 2026, 2032, 2037. A year has 53 ISO weeks when it starts on a Thursday, or starts on a Wednesday in a leap year.
Do week numbers change between countries?
The ISO 8601 numbers shown here are the same worldwide. Countries that start weeks on Sunday (US, Canada, Japan) sometimes display different numbers in local calendar apps — see week start conventions.
Can I print these charts?
Yes — every year has a printable one-page version formatted for A4 and US letter.