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Lunar Calendar
A lunar calendar is a calendar based on the monthly cycles of the Moon's phases ( synodic months, lunations), in contrast to solar calendars, whose annual cycles are based on the solar year, and lunisolar calendars, whose lunar months are brought into alignment with the solar year through some process of intercalationsuch as by insertion of a leap month. The most widely observed lunar calendar is the Islamic calendar. The details of when months begin vary from calendar to calendar, with some using new, full, or crescent moons and others employing detailed calculations. Since each lunation is approximately days, (which gives a mean synodic month as 29.53059 days or 29 days 12 hours 44 minutes and 3 seconds) it is common for the months of a lunar calendar to alternate between 29 and 30 days. Since the period of 12 such lunations, a lunar year, is 354 days, 8 hours, 48 minutes, 34 seconds (354.36707 days), lunar calendars are 11 to 12 day ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2025 Lunar Calendar
5 (five) is a number, numeral and digit. It is the natural number, and cardinal number, following 4 and preceding 6, and is a prime number. Humans, and many other animals, have 5 digits on their limbs. Mathematics 5 is a Fermat prime, a Mersenne prime exponent, as well as a Fibonacci number. 5 is the first congruent number, as well as the length of the hypotenuse of the smallest integer-sided right triangle, making part of the smallest Pythagorean triple ( 3, 4, 5). 5 is the first safe prime and the first good prime. 11 forms the first pair of sexy primes with 5. 5 is the second Fermat prime, of a total of five known Fermat primes. 5 is also the first of three known Wilson primes (5, 13, 563). Geometry A shape with five sides is called a pentagon. The pentagon is the first regular polygon that does not tile the plane with copies of itself. It is the largest face any of the five regular three-dimensional regular Platonic solid can have. A conic is det ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crescent
A crescent shape (, ) is a symbol or emblem used to represent the lunar phase (as it appears in the northern hemisphere) in the first quarter (the "sickle moon"), or by extension a symbol representing the Moon itself. In Hindu iconography, Hindu Iconography, Shiva is often shown wearing a crescent moon on his head, symbolising his control over time, as well as his attributes of both creation and destruction. It is used as the astrological symbol for Moon (astrology), the Moon, and hence as the alchemical symbol for silver. It was also the emblem of Diana (mythology), Diana/Artemis, and hence represented virginity. In veneration of Mary in the Catholic Church, it is associated with Mary, mother of Jesus. From its use as roof finial in Ottoman architecture, Ottoman mosques, it has also become associated with Islam, and the crescent was introduced as Religious symbolism in the United States military#Muslim, chaplain badge for Muslim United States military chaplains in 1993.On Dece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Javanese Calendar
The Javanese calendar () is the calendar of the Javanese people. It is used concurrently with two other calendars, the Gregorian calendar and the Islamic calendar. The Gregorian calendar is the official calendar of the Republic of Indonesia and civil society, while the Islamic calendar is used by Muslims and the Indonesian government for religious worship and deciding relevant Islamic holidays. The Javanese calendar is used by the main ethnicities of Java island—that is, the Javanese people, Javanese, Madurese people, Madurese, and Sundanese people—primarily as a cultural icon and identifier, and as a maintained tradition of antiquity. The Javanese calendar is used for cultural and spiritual purposes. The current system of the Javanese calendar was inaugurated by Sultan Agung of Mataram in the Gregorian year 1633 CE. Prior to this, the Javanese had used the Balinese saka calendar, Śaka calendar, which has its epoch in 78 CE and uses the Lunisolar calendar, lunisolar cycle fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igbo Calendar
The Igbo calendar () is the traditional calendar system of the Igbo people from present-day Nigeria. The calendar has 13 months in a year (A''fọ''), 7 weeks in a month (Ọ''nwa''), and 4 days of Igbo market days (Eke, Orie, Afọ, na Nkwọ) in a week (I''zu'') plus an extra day at the end of the year, in the last month. The name of these months was reported by Onwuejeogwu (1981). Although worship and spirit-honoring were a very big part in the creation and development of the Igbo calendar system, commerce also played a major role in creating the Igbo calendar. This was emphasized in Igbo mythology itself. An example of this is the Igbo market days of which each community has a day assigned to open its markets, this way the Igbo calendar is still in use. Some Igbo communities have tried to adjust the thirteen month calendar to twelve months, in line with the Gregorian calendar. The calendar is neither universal nor synchronized, so various groups will be at different stages of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Lunar Calendars
A lunar calendar is a calendar based on the monthly cycles of the Moon's phases (synodic months, lunations), in contrast to solar calendars, whose annual cycles are based on the solar year, and lunisolar calendars, whose lunar months are brought into alignment with the solar year through some process of intercalationsuch as by insertion of a leap month. The most widely observed lunar calendar is the Islamic calendar. The details of when months begin vary from calendar to calendar, with some using new, full, or crescent moons and others employing detailed calculations. Since each lunation is approximately days, (which gives a mean synodic month as 29.53059 days or 29 days 12 hours 44 minutes and 3 seconds) it is common for the months of a lunar calendar to alternate between 29 and 30 days. Since the period of 12 such lunations, a lunar year, is 354 days, 8 hours, 48 minutes, 34 seconds (354.36707 days), lunar calendars are 11 to 12 days shorte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utrecht University
Utrecht University (UU; , formerly ''Rijksuniversiteit Utrecht'') is a public university, public research university in Utrecht, Netherlands. Established , it is one of the oldest universities in the Netherlands. In 2023, it had an enrollment of 39,769 students, and employed 8,929 faculty members and staff. More than 400 PhD degrees were awarded and 7,765 scientific articles were published. The university's 2023 budget was €2.8 billion, consisting of €1.157 billion for the university (income from work commissioned by third parties is 319 million euros) and €1.643 billion for the University Medical Center Utrecht. The university's interdisciplinary research targets life sciences, pathways to sustainability, dynamics of youth, and institutions for open societies. Utrecht University is led by the University Board, consisting of Wilco Hazeleger (Rector Magnificus), Anton Pijpers (chair), Margot van der Starre (Vice Chair) and Niels Vreeswijk (Student Assessor). Close ties are h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leap Year
A leap year (also known as an intercalary year or bissextile year) is a calendar year that contains an additional day (or, in the case of a lunisolar calendar, a month) compared to a common year. The 366th day (or 13th month) is added to keep the calendar year synchronised with the astronomical year or seasonal year. Since astronomical events and seasons do not repeat in a Natural number, whole number of days, calendars having a constant number of days each year will unavoidably drift over time with respect to the event that the year is supposed to track, such as seasons. By inserting ("Intercalation (timekeeping), intercalating") an additional day—a leap day—or month—a leap month—into some years, the drift between a civilization's dating system and the physical properties of the Solar System can be corrected. An astronomical year lasts slightly less than 365 days. The historic Julian calendar has three common years of 365 days followed by a leap year of 366&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tabular Islamic Calendar
The Tabular Islamic calendar () is a rule-based variation of the Islamic calendar. It has the same numbering of years and months, but the months are determined by arithmetical rules rather than by observation or astronomical calculations. It was developed by early Muslim astronomers of the second hijra century (the 8th century of the Common Era) to provide a predictable time base for calculating the positions of the moon, sun, and planets. It is now used by historians to convert an Islamic date into a Western calendar when no other information (like the day of the week) is available. Its calendar era is the Hijri year. An example is the Fatimid or Misri calendar. It is used by some Muslims in everyday life, particularly in Ismaili and Shi'a communities, believing that this calendar was developed by Ali. It is believed that when Ali drew up this calendar, the previous events of the earlier prophets also fell into line with this calendar. It is their belief that all Fatimid Imam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hindu Calendar
The Hindu calendar, also called Panchangam, Panchanga (), is one of various lunisolar calendars that are traditionally used in the Indian subcontinent and Southeast Asia, with further regional variations for social and Hindu religious purposes. They adopt a similar underlying concept for timekeeping based on sidereal year for solar cycle, solar cycle and adjustment of lunar cycles in every three years, but differ in their relative emphasis to moon cycle or the sun cycle and the names of months and when they consider the New Year to start. Of the various regional calendars, the most studied and known Hindu calendars are the Shaka era, Shalivahana Shaka (Based on the Shalivahana, King Shalivahana, also the Indian national calendar) found in the Deccan Plateau, Deccan region of Southern India and the Vikram Samvat (Bikrami) found in Nepal and the North and Central regions of India – both of which emphasize the lunar cycle. Their new year starts in spring. In regions such as Tamil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Calendar
The traditional Chinese calendar, dating back to the Han dynasty, is a lunisolar calendar that blends solar, lunar, and other cycles for social and agricultural purposes. While modern China primarily uses the Gregorian calendar for official purposes, the traditional calendar remains culturally significant. It determines the timing of Chinese New Year with traditions like the twelve animals of the Chinese zodiac, Chinese Zodiac still widely observed. The traditional Chinese calendar uses the Sexagenary cycle, sexagenary cycle, a repeating system of Heavenly Stems and Earthly Branches, to mark years, months, and days. This system, along with astronomical observations and mathematical calculations, was developed to align solar and lunar cycles, though some approximations are necessary due to the natural differences between these cycles. Over centuries, the calendar was refined through advancements in astronomy and horology, with dynasties introducing variations to improve accu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hebrew Calendar
The Hebrew calendar (), also called the Jewish calendar, is a lunisolar calendar used today for Jewish religious observance and as an official calendar of Israel. It determines the dates of Jewish holidays and other rituals, such as '' yahrzeits'' and the schedule of public Torah readings. In Israel, it is used for religious purposes, provides a time frame for agriculture, and is an official calendar for civil holidays alongside the Gregorian calendar. Like other lunisolar calendars, the Hebrew calendar consists of months of 29 or 30 days which begin and end at approximately the time of the new moon. As 12 such months comprise a total of just 354 days, an extra lunar month is added every 2 or 3 years so that the long-term average year length closely approximates the actual length of the solar year. Originally, the beginning of each month was determined based on physical observation of a new moon, while the decision of whether to add the leap month was based on observation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
