Noon
day, written 12:00 in the 24-hour clock and 12:00 pm in the 12-hour clock. Midday is also used as a synonym for noon, although this may also be a more general term to mean around noon, or very early afternoon (when solar noon usually occurs).
Solar noon is when the sun appears the highest in the sky (nearest zenith), compared to its positions during the rest of the day. It occurs when the Sun is transitting the celestial meridian, exactly halfway between sunrise and sunset. This is also the origin of the terms ante meridiem and post meridiem. At solar noon, the sun is due south in the Northern Hemisphere, and due north in the Southern Hemisphere. The sun is directly overhead at solar noon at the equator on the equinoxes; at Tropic of Cancer (latitude 23½°N) on the vernal solstice in June; and at Tropic of Capricorn (23½°S) on the invernal solstice in December.
Due to the use of time zones and daylight saving time, there are few places and times where the highest point of the sun and a clock time of noon coincide.
The opposite of noon is midnight.
