d
day
Timeexact by definition
The day is exactly 86,400 seconds as a unit of measurement, that is 24 hours of 60 minutes of 60 seconds. It is not an SI unit but is accepted for use with SI, and the factor is exact by definition. It is distinct from the actual rotation period of the Earth, which is not exactly 86,400 s.
Watch out: A calendar day in UTC is not always 86,400 seconds. Leap seconds are inserted to keep UTC within 0.9 s of the Earth's rotation, making some UTC days 86,401 s long, and daylight-saving transitions make some local days 23 or 25 hours. Software that assumes a fixed day length breaks on exactly these dates. The CGPM resolved in 2022 to stop inserting leap seconds by 2035.
| 1 d | 86,400 s |
Solvers that use time