# Days until May 21

Counts the days from today, or any date you choose, to the next May 21, with its day of the week.

- Page: https://www.acalculator.org/days/days-until-may-21
- JSON spec: https://www.acalculator.org/days/days-until-may-21.json
- Version: 942f6b9279a1

## 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 233 days until May 21 on Friday, May 21, 2027.

## Inputs

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

## Outputs

| Key | Label | Description |
| --- | --- | --- |
| days | Days until May 21 | Whole days from the start date to the next May 21; 0 on the day itself. |
| date | Date | The next May 21 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 May 21 on or after the start date, then count the days from the start date to it.

## Assumptions

- May 21 comes every year, so the count is never more than 365 days.
- The start date itself is not counted: from the day before May 21, the count is 1; on May 21 itself, it is 0.
- Start dates from January 1, 1900 to December 31, 2400 work for the count to May 21, the range the date field accepts.
- Today is the date on your own device, so the count to May 21 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 = 2027-05-21 gives date = 2027-05-21, 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 = 2027-05-21, days = 140. Source: U.S. Naval Observatory, Leap Years: the Gregorian leap year rule (https://aa.usno.navy.mil/faq/leap_years).
3. from = 2027-05-22 gives date = 2028-05-21, 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 May 21?

Thursday, May 21, 2026; Friday, May 21, 2027; Sunday, May 21, 2028. The weekday of May 21 moves on one day a year, or two when a February 29 falls between.

### What day of the year is May 21?

May 21 is day 141 of a common year and day 142 of a leap year, such as 2028. Either way, 224 days of the year come after it.

### What season is May 21 in?

In the Northern Hemisphere, May 21 is in spring in every year from 2026 to 2035; in the Southern Hemisphere, it is autumn. Seasons here start on the astronomical equinoxes and solstices, dated in US Eastern Time.

### Is May 21 a US federal holiday?

No. No US federal holiday falls on May 21. The next one in the calendar after May 21 is Memorial Day, which falls between May 25 and May 31.

### How are the days until May 21 counted?

From the start date to May 21, without counting the start date: from May 20 the count is 1, and on May 21 it is 0. The day after, it moves on to the next May 21: from May 22, 2026, that is May 21, 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.