Days until September 17
September 17 falls on a Thursday in 2026 and a Friday in 2027. The count runs from today’s date on your device to the next September 17; pick another date to count from it instead.
- Days until September 17
- 352
From September 30, 2026, there are 352 days until September 17 on Friday, September 17, 2027.
- Date
- Friday, September 17, 2027
- Day of the week
- Friday
- In weeks
- 50 weeks and 2 days
Answer for the example date Wednesday, September 30, 2026. It changes to today's date when the page loads.
Days until September 17: 352. From September 30, 2026, there are 352 days until September 17 on Friday, September 17, 2027.
Where is September 17 on the calendar?
How to calculate
Counts the days from today, or any date you choose, to the next September 17, with its day of the week.
Example with the default inputs (Count from September 30, 2026) on the example date Wednesday, September 30, 2026: From September 30, 2026, there are 352 days until September 17 on Friday, September 17, 2027.
Method: Find the first September 17 on or after the start date, then count the days from the start date to it.
- September 17 comes every year, so the count is never more than 365 days.
- The start date itself is not counted: from the day before September 17, the count is 1; on September 17 itself, it is 0.
- Start dates from January 1, 1900 to December 31, 2400 work for the count to September 17, the range the date field accepts.
- Today is the date on your own device, so the count to September 17 changes at midnight where you are. Dates are whole calendar days, so a daylight-saving change never adds or loses a day.
Worked examples
Each example is checked against the calculator on every build.
- Count from 2027-09-17 gives Date 2027-09-17, Days until September 17 0.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
- Count from 2027-01-01 gives Date 2027-09-17, Days until September 17 259.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
- Count from 2027-09-18 gives Date 2028-09-17, Days until September 17 365.Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years)
Other questions people ask
What day of the week is September 17?
Thursday, September 17, 2026; Friday, September 17, 2027; Sunday, September 17, 2028. The weekday of September 17 moves on one day a year, or two when a February 29 falls between.
What day of the year is September 17?
September 17 is day 260 of a common year and day 261 of a leap year, such as 2028. Either way, 105 days of the year come after it.
What season is September 17 in?
In the Northern Hemisphere, September 17 is in summer in every year from 2026 to 2035; in the Southern Hemisphere, it is winter. Seasons here start on the astronomical equinoxes and solstices, dated in US Eastern Time.
Is September 17 a US federal holiday?
No. No US federal holiday falls on September 17. The next one in the calendar after September 17 is Columbus Day, which falls between October 8 and October 14.
How are the days until September 17 counted?
From the start date to September 17, without counting the start date: from September 16 the count is 1, and on September 17 it is 0. The day after, it moves on to the next September 17: from September 18, 2026, that is September 17, 2027, 364 days away.