How Many? A Dictionary of Units of Measurement. Traditionally, observatories had clocks set to this sidereal cycle, and astronomers still use sidereal time in making telescope settings. The sidereal hour equals 59 minutes 50.17 seconds the sidereal minute equals 59.8362 seconds the sidereal second equals 0.997 270 second. Like the regular day it is divided into 24 sidereal hours, each sidereal hour being divided into 60 sidereal minutes and each sidereal minute into 60 sidereal seconds. The sidereal day equals 23 hours 56 minutes 4.090 54 seconds, or 86 164.090 54 seconds. Thus the sidereal day, the average interval between two successive risings of the same star, is shorter than the mean solar day (see day) by 1/366.242. We only count 365.242 because one rotation is cancelled out for us by our tour around the sun. If we could view the earth from outside the Solar System, we would see that it actually completes 366.242 rotations during one year (one revolution around the sun). Sidereal day: a unit of time used in astronomy, equal to the period of time in which the earth makes one rotation relative to the stars. To convert directly from minutes to hours you multiply by 0.01 6. Simplified, this is the same as multiplying by 60/3600 which is 0.016666667. To convert from minutes to hours multiply the number of minutes by 60 and then divide by 3600. Or you can find the simplified factor by dividing the conversion factor for A by the conversion factor for B. To convert among any units in the left column, say from A to B, you can multiply by the factor for A to convert A into seconds then divide by the factor for B to convert out of seconds. This is the same as dividing 28,800 seconds by 3600 seconds per hour.
Multiply 28,800 seconds by 1/3600 hours per second.Multiply 120 minutes by 60 seconds per minuteĮxample: Convert 28,800 Seconds into Hours.The table below contains conversion factors to convert any time value into seconds using multiplication.Įxample: Convert 120 Minutes into Seconds Where S is the starting value, C is the conversion factor, andĮ is the converted result. By knowing the conversion factor, converting between units can become a simple math problem: You can use conversion factors to convert a unit of time into another using multiplication or division. This calculator does not consider the extra day in a leap year which has 366 days per year. Years in this time converter are calculated as 365 days per year.
This is equal to 365 days per year divided by 12 months per year. Months in this time conversion calculator are calculated using the average of 30.41 6 days per month. You can convert between seconds, milliseconds, microseconds, nanoseconds, days, hours, weeks, months, and years. Durations starting from 30 minutes (half an hour) are commonly used colloquially.Enter the time value and units you want to convert from, then choose the time unit you want to convert to. Most forms of employment require a certain number of hours worked per day, with compensation being based on the measured or expected hours worked. It is believed that the custom of dividing the cycle of day and night into 24 periods began with the ancient Egyptians.Ĭurrent use: The hour is used globally as a unit of time. 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.
History/origin: The term "hour" is derived from the Anglo-Norman "houre," which was in use around the 13 th century. 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. Hourĭefinition: An hour (symbol: h) is a unit of time conventionally defined as 1/24 of a day and 3,600 seconds. History/origin: The term "minute" is derived from the Latin "pars minuta prima" which means the "first small part." The minute was originally defined as 1/60 of an hour (60 seconds), based on the average period of Earth's rotation relative to the sun, known as a mean solar day.Ĭurrent use: The minute, as a multiple of the second, is used for all manner of measurements of duration, from timing races, measuring cooking or baking times, number of heart beats per minute, to any number of other applications. Under Coordinated Universal Time, a minute can have a leap second, making the minute equal to 61 rather than 60 seconds. Definition: A minute (symbol: min) is a unit of time based on the second, the base unit of the International System of Units (SI).
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