52 Monday–Sunday weeks
Every ISO 8601 week of 2025 with its code, Monday and Sunday dates, month and quarter. Select a week for its daily dates and holidays.
| Week | ISO code | Monday | Sunday | Month | Quarter |
|---|---|---|---|---|---|
| 1 | 2025-W01 | Dec/Jan | Q1 | ||
| 2 | 2025-W02 | Jan | Q1 | ||
| 3 | 2025-W03 | Jan | Q1 | ||
| 4 | 2025-W04 | Jan | Q1 | ||
| 5 | 2025-W05 | Jan/Feb | Q1 | ||
| 6 | 2025-W06 | Feb | Q1 | ||
| 7 | 2025-W07 | Feb | Q1 | ||
| 8 | 2025-W08 | Feb | Q1 | ||
| 9 | 2025-W09 | Feb/Mar | Q1 | ||
| 10 | 2025-W10 | Mar | Q1 | ||
| 11 | 2025-W11 | Mar | Q1 | ||
| 12 | 2025-W12 | Mar | Q1 | ||
| 13 | 2025-W13 | Mar | Q1 | ||
| 14 | 2025-W14 | Mar/Apr | Q2 | ||
| 15 | 2025-W15 | Apr | Q2 | ||
| 16 | 2025-W16 | Apr | Q2 | ||
| 17 | 2025-W17 | Apr | Q2 | ||
| 18 | 2025-W18 | Apr/May | Q2 | ||
| 19 | 2025-W19 | May | Q2 | ||
| 20 | 2025-W20 | May | Q2 | ||
| 21 | 2025-W21 | May | Q2 | ||
| 22 | 2025-W22 | May/Jun | Q2 | ||
| 23 | 2025-W23 | Jun | Q2 | ||
| 24 | 2025-W24 | Jun | Q2 | ||
| 25 | 2025-W25 | Jun | Q2 | ||
| 26 | 2025-W26 | Jun | Q2 | ||
| 27 | 2025-W27 | Jun/Jul | Q3 | ||
| 28 | 2025-W28 | Jul | Q3 | ||
| 29 | 2025-W29 | Jul | Q3 | ||
| 30 | 2025-W30 | Jul | Q3 | ||
| 31 | 2025-W31 | Jul/Aug | Q3 | ||
| 32 | 2025-W32 | Aug | Q3 | ||
| 33 | 2025-W33 | Aug | Q3 | ||
| 34 | 2025-W34 | Aug | Q3 | ||
| 35 | 2025-W35 | Aug | Q3 | ||
| 36 | 2025-W36 | Sep | Q3 | ||
| 37 | 2025-W37 | Sep | Q3 | ||
| 38 | 2025-W38 | Sep | Q3 | ||
| 39 | 2025-W39 | Sep | Q3 | ||
| 40 | 2025-W40 | Sep/Oct | Q4 | ||
| 41 | 2025-W41 | Oct | Q4 | ||
| 42 | 2025-W42 | Oct | Q4 | ||
| 43 | 2025-W43 | Oct | Q4 | ||
| 44 | 2025-W44 | Oct/Nov | Q4 | ||
| 45 | 2025-W45 | Nov | Q4 | ||
| 46 | 2025-W46 | Nov | Q4 | ||
| 47 | 2025-W47 | Nov | Q4 | ||
| 48 | 2025-W48 | Nov | Q4 | ||
| 49 | 2025-W49 | Dec | Q4 | ||
| 50 | 2025-W50 | Dec | Q4 | ||
| 51 | 2025-W51 | Dec | Q4 | ||
| 52 | 2025-W52 | Dec | Q4 |
2025 has 52 ISO weeks. A year gets a 53rd week only when January 1 is a Thursday, or when a leap year starts on a Wednesday.
Week 1 runs Monday, December 30, 2024 – Sunday, January 5, 2025. The last week, week 52, runs Monday, December 22 – Sunday, December 28, 2025.
Counting US-style instead (Sunday-start weeks, week 1 contains January 1), December 31, 2025, a Wednesday, falls in US week 53.
The ISO code combines the ISO year and a zero-padded week number, such as 2025-W01. The month column shows when a week crosses a month boundary. The quarter is based on the week's Thursday, which also determines its ISO year.
The first and final ISO weeks can include dates from an adjacent calendar year. Use the ISO code when a project plan must stay unambiguous.