Definition of sidereal clock in US English:

sidereal clock


  • A clock measuring sidereal time in terms of 24 equal divisions of a sidereal day.

    • ‘This firm was in business in London from about 1820 to 1840, and nearly all of the sidereal clocks which came to America during this period were made by them.’
    • ‘Like military time clocks, sidereal clocks run from 0 hours to 24 hours but they run a tiny bit faster than normal clocks, completing 24 hours in 23h 56m.’
    • ‘Because the side real day is 4 solar minutes shorter than the solar day, sidereal clocks tick at a slightly different rate than solar clocks.’
    • ‘After a year, the sidereal clock would be exactly a day faster: there are 366 sidereal days in a year.’
    • ‘In fact a sidereal clock and an ordinary clock tick at different rates because they are based upon different astronomical objects.’