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Multiple conversions
To convert from Day (d) to Nanosecond (ns), use the following formula:
To convert from Day (d) to Microsecond (mu), use the following formula:
To convert from Day (d) to Millisecond (ms), use the following formula:
To convert from Day (d) to Second (s), use the following formula:
To convert from Day (d) to Minute (min), use the following formula:
To convert from Day (d) to Hour (h), use the following formula:
To convert from Day (d) to Week (week), use the following formula:
To convert from Day (d) to Month (month), use the following formula:
To convert from Day (d) to Year (year), use the following formula:
The 24-hour day is the most basic unit we use to organize our lives. But what exactly defines a day, and is it always the same length?
A standard solar day, on which our clocks are based, is the time it takes for the Earth to rotate so that the Sun appears in the same position in the sky. This works out to be 86,400 seconds.
However, the story of a day is a bit more complex.
While we live by the 24-hour solar day, Earth's true rotation period is slightly shorter.
A sidereal day is the time it takes for Earth to rotate 360 degrees on its axis relative to distant stars. This period is actually 23 hours, 56 minutes, and 4 seconds.
So why is the solar day we use about four minutes longer? It's because while the Earth is spinning, it's also orbiting the Sun. After one full rotation (a sidereal day), it has to spin a little bit extra to "catch up" and bring the Sun back to the same point in the sky. That extra rotation time gives us our 24-hour solar day.
Yes, but don't adjust your watch just yet! The length of a day on Earth is slowly increasing.
This is due to a process called tidal braking, where the Moon's gravitational pull creates a slight drag on our planet's rotation, slowing it down.
This effect is minimal, adding only about 1.7 milliseconds to the length of a day every century. Although you may not notice it, it adds up over geological time. For example, when dinosaurs lived, a day on Earth was approximately 23 hours long.
Even though our clocks run on a steady 24-hour cycle, the actual length of a solar day (from one noon to the next) varies slightly throughout the year. The 24-hour day is just an average.
Two main factors cause this variation: