ISO week dates
When Is Week 12? Dates & Calendar
Today: · Eastern Time (America/New_York)
Week 12 dates
Week 12 of 2026
Week 12 of 2026 runs from Monday, March 16, 2026 through Sunday, March 22, 2026.
- Relevant ISO year
- 2026
- Weeks in this ISO year
- 53
- Today’s ISO week / year
- 43 / 2026
Week 12 of 2026
Each of the seven selected dates is labeled Week 12.
March 2026
| Mon | Tue | Wed | Thu | Fri | Sat | Sun |
|---|---|---|---|---|---|---|
| Week 12 | Week 12 | Week 12 | Week 12 | Week 12 | Week 12 | Week 12 |
Week 12 by ISO year
| ISO year | Monday — start | Sunday — end |
|---|---|---|
| 2024 | Mon, Mar 18, 2024 | Sun, Mar 24, 2024 |
| 2025 | Mon, Mar 17, 2025 | Sun, Mar 23, 2025 |
| 2026 | Mon, Mar 16, 2026 | Sun, Mar 22, 2026 |
| 2027 | Mon, Mar 22, 2027 | Sun, Mar 28, 2027 |
| 2028 | Mon, Mar 20, 2028 | Sun, Mar 26, 2028 |
| 2029 | Mon, Mar 19, 2029 | Sun, Mar 25, 2029 |
| 2030 | Mon, Mar 18, 2030 | Sun, Mar 24, 2030 |
| 2031 | Mon, Mar 17, 2031 | Sun, Mar 23, 2031 |
| 2032 | Mon, Mar 15, 2032 | Sun, Mar 21, 2032 |
| 2033 | Mon, Mar 21, 2033 | Sun, Mar 27, 2033 |
| 2034 | Mon, Mar 20, 2034 | Sun, Mar 26, 2034 |
Quick answers
- How many weeks are in 2026?
- 2026 has 53 ISO weeks. Week 53 does not occur every year.
- What week is it today?
- Today is in ISO week 43 of 2026.
How this is calculated
- ISO weeks run Monday through Sunday. Week 1 contains January 4 (the first Thursday of the year).
- The relevant year is the ISO week-year of today in Eastern Time (America/New_York). Near New Year, it can differ from the calendar year.
- An ISO year has 52 or 53 weeks. Week 53 exists only in applicable ISO years; it is never rolled into Week 1.