Days until September
September 2027 starts on Wednesday, September 1, 2027. The count starts from today’s date; pick another date to count from it instead.
- Days until September
- 336
From September 30, 2026, there are 336 days until September on Wednesday, September 1, 2027.
- Date
- Wednesday, September 1, 2027
- Day of the week
- Wednesday
- In weeks
- 48 weeks
- In months and days
- 11 months, 2 days
Answer for the example date Wednesday, September 30, 2026. It changes to today's date when the page loads.
Days until September: 336. From September 30, 2026, there are 336 days until September on Wednesday, September 1, 2027.
Where is September on the calendar?
How to calculate
Counts the days from today, or any date you choose, to September 1, the first day of the next September, with its weekday and the time in weeks and months.
Example with the default inputs (Count from September 30, 2026) on the example date Wednesday, September 30, 2026: From September 30, 2026, there are 336 days until September on Wednesday, September 1, 2027.
Method: Find the first September 1 on or after the start date, then count the days from the start date to it.
- The count is to September 1, the first day of the month. During September, it counts to September 1 of the next year.
- The start date itself is not counted: from the day before, the count is 1; on the day itself, it is 0.
- Dates are calendar days with no time of day, so a time zone or a daylight-saving change never adds or loses a day.
- Start dates from January 1, 1900 to December 31, 2400 work.
Worked examples
Each example is checked against the calculator on every build.
- Count from 2026-09-28 gives Date 2027-09-01, Days until September 338, Day of the week Wednesday.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
- Count from 2026-09-01 gives Date 2026-09-01, Days until September 0, Day of the week Tuesday.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
- Count from 2026-09-02 gives Date 2027-09-01, Days until September 364, Day of the week Wednesday.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
- Count from 2028-02-29 gives Date 2028-09-01, Days until September 185, Day of the week Friday.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
Other questions people ask
When does September 2027 start?
September 2027 starts on Wednesday, September 1, 2027 and ends on Thursday, September 30, 2027.
How many days are in September?
September always has 30 days, so September 2027 runs from Wednesday, September 1, 2027 to Thursday, September 30, 2027.
What day of the week does September 2028 start on?
September 2028 starts on a Friday: Friday, September 1, 2028.
What if it is already September?
The page counts to the first day of the month. On September 1 the count is 0; from September 2 to September 30 it counts to September 1 of the next year. From Thursday, September 2, 2027, that is Friday, September 1, 2028.
How are the days until September counted?
From the start date (today, unless you change it) to September 1, without counting the start date: from the last day of the month before, the count is 1. The weeks and months shown are the same span, in whole weeks and in whole months plus days.