The day equals 24 hours and is based on Earth's rotation cycle.
One of the oldest time units in human history, directly tied to the day-night cycle.
Measurement system: SI-compatible, natural unit. SI equivalent: 1 day = 86,400 s = 24 hours.
Day facts
- Unit name
- Day
- Symbol
- day
- Category
- Time
- Measurement system
- SI-compatible, natural unit
- SI equivalent
- 1 day = 86,400 s = 24 hours
- Common uses
- Calendars, age calculations and planning
Definition of the day
The day equals 24 hours and is based on Earth's rotation cycle.
Measurement system and SI relationship
SI-compatible, natural unit
SI equivalent: 1 day = 86,400 s = 24 hours
History of the day
One of the oldest time units in human history, directly tied to the day-night cycle.
Where is the day used?
Calendars, age calculations and planning