# Days until September 30

Counts the days from today, or any date you choose, to the next September 30, with its day of the week.

- Page: https://www.acalculator.org/days/days-until-september-30
- JSON spec: https://www.acalculator.org/days/days-until-september-30.json
- Version: 85850ca91d33

## Default answer

Example with the default inputs (Count from September 30, 2026) on the example date Wednesday, September 30, 2026: From September 30, 2026, there are 0 days until September 30 on Wednesday, September 30, 2026.

## Inputs

| Key | Label | Description |
| --- | --- | --- |
| from | Count from | The date to count from. Today, unless you change it. |

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| days | Days until September 30 | Whole days from the start date to the next September 30; 0 on the day itself. |
| date | Date | The next September 30 on or after the start date. |
| weekday | Day of the week | The weekday of that date. |
| weeks | In weeks | The same number of days in weeks and days. |

## Method

Find the first September 30 on or after the start date, then count the days from the start date to it.

## Assumptions

- September 30 comes every year, so the count is never more than 365 days.
- The start date itself is not counted: from the day before September 30, the count is 1; on September 30 itself, it is 0.
- Start dates from January 1, 1900 to December 31, 2400 work for the count to September 30, the range the date field accepts.
- Today is the date on your own device, so the count to September 30 changes at midnight where you are. Dates are whole calendar days, so a daylight-saving change never adds or loses a day.

## Worked examples

1. from = 2027-09-30 gives date = 2027-09-30, days = 0. Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years).
2. from = 2027-01-01 gives date = 2027-09-30, days = 272. Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years).
3. from = 2027-10-01 gives date = 2028-09-30, days = 365. Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years).

## FAQ

### What day of the week is September 30?

Wednesday, September 30, 2026; Thursday, September 30, 2027; Saturday, September 30, 2028. The weekday of September 30 moves on one day a year, or two when a February 29 falls between.

### What day of the year is September 30?

September 30 is day 273 of a common year and day 274 of a leap year, such as 2028. Either way, 92 days of the year come after it.

### What season is September 30 in?

In the Northern Hemisphere, September 30 is in fall in every year from 2026 to 2035; in the Southern Hemisphere, it is spring. Seasons here start on the astronomical equinoxes and solstices, dated in US Eastern Time.

### Is September 30 a US federal holiday?

No. No US federal holiday falls on September 30. The next one in the calendar after September 30 is Columbus Day, which falls between October 8 and October 14.

### How are the days until September 30 counted?

From the start date to September 30, without counting the start date: from September 29 the count is 1, and on September 30 it is 0. The day after, it moves on to the next September 30: from October 1, 2026, that is September 30, 2027, 364 days away.

## Sources

- 5 U.S.C. 6103 (federal holidays; weekend rule in 6103(b) and Executive Order 11582). Checked against OPM holiday schedules.
- Equinoxes and solstices: Jean Meeus, Astronomical Algorithms (2nd ed., 1998), chapter 27, checked against the US Naval Observatory.