Which Years Have 53 Weeks?
Direct answer
2026 has 53 ISO weeks. Most ISO years have 52 weeks, but some have 53 depending on how weekdays align with January 1.
From 2020 through 2050, the years with 53 ISO weeks are 2020, 2026, 2032, 2037, 2043, 2048.
After 2026, the next 53-week ISO year is 2032. Its Week 53 runs from 2032-12-27 to 2033-01-02.
ISO weeks by year: 2020–2050
Use this table to check whether an ISO week-year has 52 or 53 weeks. It is not a count of weeks or paydays in a calendar year.
| Year | ISO weeks | Has Week 53? |
|---|---|---|
| 2020 | 53 | Yes |
| 2021 | 52 | No |
| 2022 | 52 | No |
| 2023 | 52 | No |
| 2024 | 52 | No |
| 2025 | 52 | No |
| 2026 | 53 | Yes |
| 2027 | 52 | No |
| 2028 | 52 | No |
| 2029 | 52 | No |
| 2030 | 52 | No |
| 2031 | 52 | No |
| 2032 | 53 | Yes |
| 2033 | 52 | No |
| 2034 | 52 | No |
| 2035 | 52 | No |
| 2036 | 52 | No |
| 2037 | 53 | Yes |
| 2038 | 52 | No |
| 2039 | 52 | No |
| 2040 | 52 | No |
| 2041 | 52 | No |
| 2042 | 52 | No |
| 2043 | 53 | Yes |
| 2044 | 52 | No |
| 2045 | 52 | No |
| 2046 | 52 | No |
| 2047 | 52 | No |
| 2048 | 53 | Yes |
| 2049 | 52 | No |
| 2050 | 52 | No |
Why does 2026 have 53 weeks?
2026 starts on a Thursday. Under ISO rules, that alignment creates 53 full ISO week numbers in the ISO week-year.
View the 2026 calendar or open Week 53, 2026.
ISO 53-week rule
An ISO year has 53 weeks when January 1 falls on Thursday, or when January 1 falls on Wednesday in a leap year. Another way to check the same rule is to look at December 31: if it falls on Thursday, or Friday in a leap year, the ISO year has Week 53.
Planning edge cases
| ISO week | Date range | Planning note |
|---|---|---|
| 2026-W01 | 2025-12-29 to 2026-01-04 | The ISO year starts before calendar year 2026. |
| 2026-W53 | 2026-12-28 to 2027-01-03 | The final ISO week crosses into calendar year 2027. |
| 2027-W01 | 2027-01-04 to 2027-01-10 | January 1–3 still belong to 2026-W53; Week 1 starts on Monday, January 4. |
Plan the transition with the Week 53 date table and 2027 week-number calendar.
Does 53 ISO weeks mean 53 paydays?
No. ISO week-years are not the same as payroll schedules or 52/53-week fiscal calendars. Paydays depend on the chosen payment dates, and fiscal periods follow the organization's own calendar.
For example, 2026-W53 includes three dates in January 2027. Keep the ISO week-year and the calendar date in separate columns when planning or reporting, and check your employer's schedule before using week numbers for payroll.
Use an ISO week-year formula in Excel or convert a week number to its dates.