Solar noon 

Noon (also midday) is the hour of 12:00 in an observer's local time zone, or more loosely, a time near the middle of the day when workers in many countries take a meal break. The scientific term solar noon describes the moment when the sun crosses the meridian in apparent solar time.

The opposite of noon is midnight.

Etymology

The word "noon" is derived from Latin nona hora, the ninth hour of the day. The Roman and Western European medieval monastic day began at 6:00 am (0600) by modern timekeeping, so the ninth hour began at what is now 2:00 pm (1400). In English, the meaning of the word shifted to midday by the year 1100 CE.1

Solar noon

Solar noon is the moment when the sun appears the highest in the sky (nearest zenith), compared to its positions during the rest of the year. It occurs when the Sun is transitting the celestial meridian. This is also the origin of the terms ante meridiem and post meridiem as noted above. The Sun is directly overhead at solar noon at the equator on the equinoxes; at Tropic of Cancer (latitude 23° 26′ 22″ N) on the June solstice; and at Tropic of Capricorn (23° 26′ 22″ S) on the December solstice.

Due to the different locations within a single time zone, it is largely a coincidence that at your particular longitude the instant of solar noon would occur at the local clock time noon - but it does occur at some location within your time zone every day, at a different precise longitude every day.

See also

References

  1. ^ Online Etymology Dictionary

External links