Mondays in September 2025: the 1st, 8th, 15th, 22nd and 29th
There are 5 Mondays in September 2025, falling on September 1, September 8, September 15, September 22 and September 29. The month runs 30 days, opens on a Monday and closes on a Tuesday.
Every Monday in September 2025
| # | Date | Day of year |
|---|---|---|
| 1 | September 1, 2025 | 244 |
| 2 | September 8, 2025 | 251 |
| 3 | September 15, 2025 | 258 |
| 4 | September 22, 2025 | 265 |
| 5 | September 29, 2025 | 272 |
Why five and not four?
Four weeks account for exactly 28 days, so every month is guaranteed four of each weekday. September 2025 runs 30 days, which leaves 2 days beyond four whole weeks, falling on Monday and Tuesday. Monday is among them, which is why it appears a fifth time, on September 29.
Five Mondays and the payroll question
A month with five Mondays matters to anyone paid weekly or fortnightly on that day, because it produces an extra pay date inside the same calendar month. In 2025 that happens in March, June, September, December, so September 2025 is one of 4 months this year.
Mondays in September across other years
The same month shifts forward a weekday each year, and two across a leap year, so the answer moves with it.
| Year | Mondays | Dates |
|---|---|---|
| September 2024 | 5 | 2, 9, 16, 23, 30 |
| September 2026 | 4 | 7, 14, 21, 28 |
| September 2027 | 4 | 6, 13, 20, 27 |
| September 2028 | 4 | 4, 11, 18, 25 |
| September 2029 | 4 | 3, 10, 17, 24 |
| September 2030 | 5 | 2, 9, 16, 23, 30 |
Questions
- How many Mondays are in September 2025?
- 5 Mondays, on September 1, September 8, September 15, September 22 and September 29.
- What is the first Monday in September 2025?
- September 1, 2025. The last is September 29.
- How many Mondays are there in 2025 altogether?
- 52 Mondays across the year. The 2025 breakdown lists them month by month.
- Does every month have four Mondays?
- Every month has at least four, because four weeks fill 28 days. A fifth only appears when the spare days at the end of the month reach another Monday.
Nearby months
Other weekdays in September 2025
All Mondays in 2025 · What day is September 1 · Business day calculator