solar time; apparent solar time; mean solar time
Meanings
3 senses · 6 examplesnoun
solar time; time calculated according to the solar day
technicalEncompasses both true solar time (apparent solar time) and mean solar time. Used in astronomy and timekeeping.
Solar time is a timekeeping system determined by the position of the sun.
Ancient times used solar time to arrange agricultural activities.
noun
true solar time; apparent solar time (time calculated according to the true solar day; indicated by sundials)
technicalAlso called 视太阳时 or 真时. Measured by sundials, it varies throughout the year due to Earth's elliptical orbit and axial tilt. Differs from clock time by up to ±16 minutes.
The sundial shows true solar time.
There is a time difference between true solar time and mean solar time.
noun
mean solar time (time calculated according to the mean solar day; indicated by clocks)
technicalAlso called 平时. Used by ordinary clocks and watches. It averages out the variations in true solar time to create uniform 24-hour days.
Clocks show mean solar time.
We use mean solar time in our daily lives.