Year
In astronomy, the Julian year is a unit of time; it is defined as 365.25 days of exactly 86,400 seconds (SI base unit), totalling exactly 31,557,600 seconds in the Julian astronomical year.
List of unusual units of measurement
George Gamow discussed measurements of time such as the "light-mile" and "light-foot", the time taken for light to travel the specified unit distance, defined by "reversing the procedure" used in defining a light-year. One light-nanosecond is roughly 30 centimeters (29.9792458 cm exactly), or about a foot (30.48 cm).