What Number Month Is September? September Is the 9th Month
Quick answer • Month name to number converter • Full reference table
If you’ve ever wondered what number month is September, you’re not alone. Whether you’re filling out forms, planning events, or working with dates, knowing that September is the 9th month is essential. But why stop at September? Our tool instantly converts any month name to its number and vice versa.
Below you’ll find the clear answer, a handy converter, and lots of useful facts about September and the calendar.
September Month Number & Converter
📋 Months of the Year Reference
| Month | Number | Days | Season (Northern) |
|---|---|---|---|
| January | 1 | 31 | Winter |
| February | 2 | 28/29 | Winter |
| March | 3 | 31 | Spring |
| April | 4 | 30 | Spring |
| May | 5 | 31 | Spring |
| June | 6 | 30 | Summer |
| July | 7 | 31 | Summer |
| August | 8 | 31 | Summer |
| September | 9 | 30 | Autumn |
| October | 10 | 31 | Autumn |
| November | 11 | 30 | Autumn |
| December | 12 | 31 | Winter |
📋 How to use
See instant answer: September = 9
Select any month to get its number
Enter a number to get the month name
Why knowing the month number matters
Whether you’re working with spreadsheets, programming dates, or just planning, month numbers are everywhere. For example, September’s month number is 9, which is useful for date formatting (MM/DD/YYYY), fiscal year planning, and historical references.
Common uses:
- Spreadsheet formulas: =MONTH(“September 15, 2025”) returns 9.
- Database queries: Filtering records from September (month = 9).
- Event planning: September is the 9th month, so it’s the start of autumn.
- Astrology & birthstones: September’s number corresponds to Virgo/Libra cusp and Sapphire.
Fun facts about September
- Name origin: From the Latin word “septem,” meaning seven, because it was the seventh month in the early Roman calendar (before January and February were added).
- Birth flowers: Aster and Morning Glory.
- Birthstone: Sapphire.
- Zodiac signs: Virgo (until September 22) and Libra (September 23 onward).
- Holidays: Labor Day (US, first Monday), Patriot Day (September 11), and the autumn equinox (around September 22).
How to remember September is the 9th month
Think of “September” and remember that “Sept” means seven, but because of calendar changes, it’s actually the 9th month. Or use the knuckle trick: September is in the valley between knuckles (30 days), and it’s the ninth position if you start with January on the first knuckle.
Another way: “September” rhymes with “remember,” and you need to remember it’s the 9th!
Frequently Asked Questions
What number month is September?
September is the 9th month of the year. It comes after August (8) and before October (10).
How many days does September have?
September has 30 days, like April, June, and November.
Is September the 9th or 10th month?
September is the 9th month. October is the 10th. Despite “Sept” meaning seven, it’s now the ninth.
What number is September in a calendar year?
In the Gregorian calendar, September is month number 9.
What is the month number for December?
December is the 12th month. You can use the converter above to find any month’s number.
Why is September called September?
It comes from the Latin “septem” meaning seven, because it was the seventh month in the ancient Roman calendar (which started in March).