Noon (also mid-day or noon time) 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 time during a day with the highest sun elevation, which depends on longitude, latitude and date ^[1].

The opposite of noon is midnight.

In the northern hemisphere, "noon" had an ancient geographic association with "south" (as did midnight with "north"). Remnants of the "noon" association are preserved in the words for "noon" in French ("midi") and Italian ("mezzogiorno"), both of which also refer to the southern parts of the respective countries. Modern Polish goes a step farther, with the words for noon ("południe" -- literally "mid-day") also meaning "south" and the word for "midnight" ("północ" -- literally "mid-night") also meaning "north".

[edit] 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 starts at what is now 2:00 pm (1400). In English, the meaning of the word shifted to midday by the fourteenth century.^[2]

[edit] 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 day. 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 below. 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 a particular longitude the instant of solar noon would occur at the local clock time noon - but it does occur at some location within a given time zone every day that daylight saving time is not observed, at a different precise longitude every day. It can be (approximately) calculated for any given longitude and any given day since January 1, 2000 using the following equation:

approximate solar noon

where:

J_date is the Julian date;

l_w is the longitude west (west is positive, east is negative) of the observer on the Earth;

[edit] Nomenclature

In 24-hour time notation, "12:00" and "12:00:00" refer to noon at the middle of a given date.

With 12-hour time notation, most authorities recommend avoiding confusion by using "noon," "12 noon," or "12:00 noon."

Digital clocks and computers commonly display 12 p.m. for noon. While that phrase may be used practically, it helps to understand that any particular time is actually an instant. The "p.m." shown on clock displays refers to the 12-hour period following the instant of noon, not to the instant itself. In other words, 11:59 a.m. shows until noon; at the instant of noon it flips to 12:00.

While computers and digital clocks display "12:00 a.m." and "12:00 p.m." these notations provide no clear and unambiguous way to distinguish between midnight and noon. It is actually improper to use "a.m." and "p.m." when referring to 12:00. The abbreviation a.m. stands for ante meridian or before the meridian and p.m. stands for post meridian or after the meridian, the meridian being 12:00. Since noon and midnight are neither after 12:00 nor before 12:00 but ARE 12:00, neither abbreviation is or possibly can be correct. The length of the error is determined by the smallest unit of time: 12:00:01 p.m. would be correctly notated, as would even 12:00:00.000 . . . 1 pm.

The most common ways to represent these times are, (a) to use a 24-hour clock (00:00 and 12:00, 24:00), (b) to use "12 noon" or "12 midnight," although unless the person is referring to a general time and not a specific day, "12 midnight" is still ambiguous, (c) to specify midnight as between two successive days or dates (Midnight Saturday/Sunday or Midnight December 14/15), and (d) to use "12:01 p.m." or "11:59 a.m." This final usage is common in the travel industry, especially train and plane schedules, to avoid confusion as to passengers' schedules.

The 30th edition of the U.S. Government Style Manual (2008) sections 9.54 and 12.9b recommends the use of "12 a.m." for midnight and "12 p.m." for noon.^{[3][4][nb 1]}

[edit] Cultural meanings

In traditional magical thinking, both noon and its opposite, midnight, form an axis linking the mundane world with otherworlds by being apogee of light and darkness, respectively. Thus, noon is associated with heaven, order and life.

[edit] Touching the sacrum

Central points of day and night were seen as moments when sacrum manifests itself and epiphanies were most likely. Thus, a noon prayer, healing practice and ritual magic were thought to be most effective - if their intentions were related to themes associated with day, of course. Also, numerous plants, animals, substances and other items harvested at noon were believed to have special, magical qualities and powers helpful in ritual practices.

[edit] Sun resting

As it seems, the Sun stops its voyage at noon, where it was thought to rest for a while. By standards of magical thinking this stillness is sacred, as Otherworlds themselves are still and static. It was thought that at noon, Otherworld pristine conditions were present, bringing the state of primordial chaos to the world.

This resulted in the taboo of working at noon, as work is associated with culture and civilization and therefore anathema to nature and chaos. So, the act of working at noon is viewed as human will contradicting the natural (or God-given) order. As a result, in folklore there is widespread belief that working at noon is vainly and even harmful.

[edit] Demons of noon

Persons breaking the taboo of working at noon were subject to chastisement by demons of noon. They are present in many mythologies, from Islamic and Hebrew mythology, where they were represented by dust devils, to Slavic mythology, where all sorts of poludnicas, wilas, and topielecs haunted the offending folk at noon. They universally caused hyperthermia resulting in aches, maddness or drowning.^[5]

[edit] Notes

1. ^ The 29th edition of the U.S. Government Printing Office Style Manual (2000) section 12.9 recommended the opposite the use of "12 p.m." for midnight and "12 a.m." (formerly "12 m.") for noon.

[edit] See also

• 12-hour clock
• Dipleidoscope
• Midafternoon
• Midnight
• Hour angle
• Solar azimuth angle

[edit] References

[edit] External links

• Media related to Noon at Wikimedia Commons
• Generate a solar noon calendar for your location
• U.S. Government Printing Office Style Manual (2008), 30th edition

v • d • e Parts of a day Dawn–Twilight–Sunrise • Morning • Noon • Afternoon • Evening • Sunset–Twilight–Dusk • Night • Midnight Related articles : Blue hour  · Terminator  · Daytime  · White nights