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The traditional Chinese calendar is a lunisolar calendar, combining the solar, lunar, and other cycles for various social and religious purposes. More recently, in China and Chinese communities the Gregorian calendar has been adopted and adapted in various ways, and is generally the basis for standard civic purposes, but incorporating traditional lunisolar holidays. However, there are many types and subtypes of the Chinese calendar, partly reflecting developments in astronomical observation and horology, with over a millennium plus history. The major modern form is the Gregorian calendar-based official version of the Mainland China, although diaspora versions are also notable in other parts of China and Chinese-influenced cultures; however, aspects of the traditional lunisolar calendar remain popular, including the association of the twelve animals of the Chinese Zodiac in relation to months and years.
A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September.
The full moon is the lunar phase when the Moon appears fully illuminated from Earth's perspective. This occurs when Earth is located between the Sun and the Moon. This means that the lunar hemisphere facing Earth—the near side—is completely sunlit and appears as an approximately circular disk. The full moon occurs roughly once a month.
A month is a unit of time, used with calendars, that is approximately as long as a natural orbital period of the Moon; the words month and Moon are cognates. The traditional concept of months arose with the cycle of Moon phases; such lunar months ("lunations") are synodic months and last approximately 29.53 days, making for roughly 12.37 such months in one Earth year. From excavated tally sticks, researchers have deduced that people counted days in relation to the Moon's phases as early as the Paleolithic age. Synodic months, based on the Moon's orbital period with respect to the Earth–Sun line, are still the basis of many calendars today and are used to divide the year.
A lunar phase or Moon phase is the apparent shape of the Moon's directly sunlit portion as viewed from the Earth. In common usage, the four major phases are the new moon, the first quarter, the full moon and the last quarter; the four minor phases are waxing crescent, waxing gibbous, waning gibbous, and waning crescent. A lunar month is the time between successive recurrences of the same phase: due to the eccentricity of the Moon's orbit, this duration is not perfectly constant but averages about 29.5 days.
In astronomy, the new moon is the first lunar phase, when the Moon and Sun have the same ecliptic longitude. At this phase, the lunar disk is not visible to the naked eye, except when it is silhouetted against the Sun during a solar eclipse.
The Northern Hemisphere is the half of Earth that is north of the Equator. For other planets in the Solar System, north is defined as being in the same celestial hemisphere relative to the invariable plane of the Solar System as Earth's North Pole.
A solstice is an event that occurs when the Sun reaches its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes.
Summer is the hottest and brightest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, daylight hours are the longest and darkness hours are the shortest, with day length decreasing as the season progresses after the solstice. The earliest sunrises and latest sunsets also occur near the date of the solstice. The date of the beginning of summer varies according to climate, tradition, and culture. When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere, and vice versa.
The term dark moon describes the last visible crescent of a waning Moon. The duration of a dark moon varies between 1.5 and 3.5 days, depending on its ecliptic latitude. In current astronomical usage, the new moon occurs in the middle of this dark period, when the Moon and Sun are in conjunction. This definition has entered popular usage, so that calendars will typically indicate the date of the "new moon" rather than the "dark moon".
Sunset is the disappearance of the Sun below the horizon of the Earth due to its rotation. As viewed from everywhere on Earth, it is a phenomenon that happens approximately once every 24 hours, except in areas close to the poles. The equinox Sun sets due west at the moment of both the spring and autumn equinoxes. As viewed from the Northern Hemisphere, the Sun sets to the northwest in the spring and summer, and to the southwest in the autumn and winter; these seasons are reversed for the Southern Hemisphere.
"Once in a blue moon" is a traditional phrase of unknown origin meaning "very rarely indeed". Webster's Dictionary (1949) defined a blue moon as meaning, "A phenomenon never, or very rarely, seen; hence, a rarely recurring occasion." However, since the mid-20th century the term blue moon has commonly been applied to the occurrence of a second full moon within a single calendar month, something that happens every two or three years, thus obscuring the original meaning of the term.
Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June and December.
The Attic calendar or Athenian calendar is the lunisolar calendar beginning in midsummer with the lunar month of Hekatombaion, in use in ancient Attica, the ancestral territory of the Athenian polis. It is sometimes called the Greek calendar because of Athens's cultural importance, but it is only one of many ancient Greek calendars.
The September equinox is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur from September 21 to 24.
The March equinox or northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox in the Northern Hemisphere and as the autumnal equinox in the Southern Hemisphere.
Though no standard exists, numerous calendars and other timekeeping approaches have been proposed for the planet Mars. The most commonly seen in the scientific literature denotes the time of year as the number of degrees on its orbit from the northward equinox, and increasingly there is use of numbering the Martian years beginning at the equinox that occurred April 11, 1955.
A total lunar eclipse occurred on 31 January 2018. The Moon was near its perigee on 30 January and as such may be described as a "supermoon", when the Moon's distance from the Earth is less than 360,000 km. The previous supermoon lunar eclipse was in September 2015.
A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical cultures whose number of seasons varies.
The Hindu calendar is based on a geocentric model of the Solar System. A geocentric model describes the Solar System as seen by an observer on the surface of the Earth.
References
- ↑ The earliest source appears to be the 2016 on-line article on "Time and Date" referenced below: it does mention but does not properly refer to "astrology" and "wicca", so this appears to be a recent invention modeled after Blue moon.
- 1 2 3 4 5 6 7 8 9 10 11 "What Is a Black Moon?". Time and Date. Retrieved 3 October 2016.
- 1 2 3 "Black Moon". The Moon FAQs. Retrieved 3 October 2016.
- 1 2 3 4 5 David Harper (2015). "Two New Moons in one month" . Retrieved 3 October 2016.
- 1 2 Sten Odenwald (2004). "Is there a name for the second New Moon in a month?". Ask the Astronomer. Retrieved 3 October 2016.
- ↑ Fraser Cain (24 December 2015). "Black moon". Universe Today. Retrieved 3 October 2016.
- 1 2 3 Joe Rao (30 September 2016). "Black Moon 2016: What It Is (and Why You Can't See It)". Space.com. Retrieved 3 October 2016.
- ↑ Dorothy Morrison (2004). Everyday Moon Magic Spells & Rituals for Abundant Living. Llewellyn Publications. p. 43. ISBN 0-7387-0249-8.
- 1 2 3 "Black Moon". Witchipedia. Archived from the original on 21 October 2019. Retrieved 3 October 2016.
- 1 2 3 4 "Phases of the Moon". Data Services. Astronomical Applications Department, U.S. Naval Observatory. Archived from the original on 30 September 2016. Retrieved 4 October 2016.
- 1 2 3 4 "Phases of the Moon 2000-2049 - Navy.mil" (PDF). US Naval Office. 4 November 1986.
- ↑ "Moonlore". The Celtic Connection. Archived from the original on 16 October 2016. Retrieved 3 October 2016.
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