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Convert days to hours

Please provide values below to convert day [d] to hour [h], or vice versa.



Definition: A day (symbol: d) is an accepted, non-SI unit of time that is defined based on the SI (International System of Units) unit of time, the second, and is equal to 86,400 seconds.

History/origin: The term "day" originates from the Old English term "dæg." It is approximately equal to the period required for the Earth to complete a full rotation with respect to the sun. This was later re-defined in terms of the second in 1960, when the second was redefined in terms of Earth's orbital motion in the year 1900. The second, and therefore the day, was again re-defined in 1967 by atomic electron transition.

Current use: The day is a term used worldwide within many contexts one of the most common of which is to refer to a time interval of 24 hours. It is also used to reference daytime, or the period of time during which the sun is above the horizon. The term also has other colloquial uses such as the day of the week and fixed clock periods like 6:00 am to 6:00 pm, among others.


Definition: An hour (symbol: h) is a unit of time conventionally defined as 1/24 of a day and 3,600 seconds. In Coordinated Universal Time, a negative or positive leap second may be incorporated to keep the hour within 0.9 seconds of universal time, making an hour either 3,599 or 3,601 seconds in some cases.

History/origin: The term "hour" is derived from the Anglo-Norman "houre," which was in use around the 13th century.

There have been many definitions of the hour throughout history based on culture or region, such as the hour being divided into 1/12 of a period daylight or darkness. It is believed that the custom of dividing the cycle of day and night into 24 periods began with the ancient Egyptians.

Current use: The hour is used globally as a unit of time. Most forms of employment require a certain number of hours worked per day, with compensation being based on the measured or expected hours worked. Durations starting from 30 minutes (half an hour) are commonly used colloquially.

Day to Hour Conversion Table

Day [d]Hour [h]
0.01 d0.24 h
0.1 d2.4 h
1 d24 h
2 d48 h
3 d72 h
5 d120 h
10 d240 h
20 d480 h
50 d1200 h
100 d2400 h
1000 d24000 h

How to Convert Day to Hour

1 d = 24 h
1 h = 0.0416666667 d

Example: convert 15 d to h:
15 d = 15 × 24 h = 360 h

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