September 13, 2027 falls on a Monday
September 13, 2027 is a Monday. It is 355 days from today, September 23, 2026. The date is day 256 of 365 in 2027, it sits in ISO week 37, and it is the 13th of a 30-day month with 17 days after it.
What day of the week is September 13?
In 2027 it is a Monday. The weekday is not a property of the date itself, it is a property of the date in a given year, so the honest answer always names the year. A common year is 365 days, which is 52 weeks plus one spare day, so a fixed date moves forward one weekday from one year to the next. A leap year inserts a second spare day, so the step is two whenever 29 February falls inside the gap. That is why September 13 works its way around the week rather than repeating on a tidy schedule.
September 13 in the next few years
| Year | Weekday | Day of year | ISO week | Leap year |
|---|---|---|---|---|
| 2026 | Sunday | 256 | 37 | no |
| 2027 | Monday | 256 | 37 | no |
| 2028 | Wednesday | 257 | 37 | yes |
| 2029 | Thursday | 256 | 37 | no |
| 2030 | Friday | 256 | 37 | no |
| 2031 | Saturday | 256 | 37 | no |
| 2032 | Monday | 257 | 38 | yes |
| 2033 | Tuesday | 256 | 37 | no |
Between 2026 and 2027 the weekday moves from Sunday to Monday, a step of 1. The day-of-year column also moves: September 13 is day 256 in a common year and day 257 in a leap year, because it sits after 29 February.
How often does September 13 fall at a weekend?
Counting the 28 occurrences from 2027 to 2054, September 13 lands on a Saturday 4 times and on a Sunday 4 times, so 8 of those 28 years put it at a weekend. Over a full 28-year stretch the Gregorian calendar repeats itself, and a fixed date visits each weekday four times, so the long-run answer is two weekend years in every seven.
Where September 13 sits in the calendar
September 13 is the 13th day of September, a month of 30 days in 2027, leaving 17 days of the month after it. Measured from 1 January it is 255 days into the year, and 109 days remain to 31 December, which puts it 70.1% of the way through 2027. In September 2027 the other Mondays are the 6th, 20th, 27th, because weekdays repeat every seven days inside a month just as they do across one.
What else happens around September 13?
| Date | Occasion | Type | Days from September 13 |
|---|---|---|---|
| September 11 | Patriot Day | observance | 2 before |
How far away is September 13?
The next September 13 is Monday, September 13, 2027, 355 days from today. That is 50 whole weeks and 5 days, or 50.7 weeks written as a decimal. To count towards it second by second, use the date calculator.
Questions
- What day of the week is September 13, 2027?
- A Monday. It is day 256 of 365 and falls in ISO week 37.
- What day of the week is September 13 next year?
- In 2027 it is a Monday.
- What number day of the year is September 13?
- Day 256 in a common year and day 257 in a leap year. See day 256 for more.
- Which week of the year is September 13 in?
- ISO week 37 in 2027. The week 37 page lists every date in it.
Nearby dates
The 13th of other months
All 366 dates · Week 37 · Day 256 of the year · Event countdowns · When is it? · Date calculator