April is the fourth month of the year in the Gregorian and Julian calendars. Its length is 30 days.
August is the eighth month of the year in the Julian and Gregorian calendars. Its length is 31 days.
December is the twelfth and final month of the year in the Julian and Gregorian calendars. Its length is 31 days.
February is the second month of the year in the Julian and Gregorian calendars. The month has 28 days in common years and 29 in leap years, with the 29th day being called the leap day. February is the third and last month of meteorological winter in the Northern Hemisphere. In the Southern Hemisphere, February is the third and last month of meteorological summer, being the seasonal equivalent of August in the Northern Hemisphere.
January is the first month of the year in the Julian and Gregorian calendars. Its length is 31 days. The first day of the month is known as New Year's Day. It is, on average, the coldest month of the year within most of the Northern Hemisphere and the warmest month of the year within most of the Southern Hemisphere. In the Southern hemisphere, January is the seasonal equivalent of July in the Northern hemisphere and vice versa.
June—abbreviated Jun—is the sixth month of the year in the Julian and Gregorian calendars—the latter the most widely used calendar in the world. Its length is 30 days. June succeeds May and precedes July. This month marks the start of summer in the Northern Hemisphere and contains the summer solstice, which is the day with the most daylight hours. In the Southern Hemisphere, June is the start of winter and contains the winter solstice, the day with the fewest hours of daylight out of the year.
July is the seventh month of the year in the Julian and Gregorian calendars. Its length is 31 days. It was named by the Roman Senate in honour of Roman general Julius Caesar in 44 B.C., being the month of his birth. Before then it was called Quintilis, being the fifth month of the calendar that started with March.
A leap year is a calendar year that contains an additional day compared to a common year. The 366th day 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 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 ("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.
March is the third month of the year in both the Julian and Gregorian calendars. Its length is 31 days. In the Northern Hemisphere, the meteorological beginning of spring occurs on the first day of March. The March equinox on the 20 or 21 marks the astronomical beginning of spring in the Northern Hemisphere and the beginning of autumn in the Southern Hemisphere, where September is the seasonal equivalent of the Northern Hemisphere's March.
May is the fifth month of the year in the Julian and Gregorian calendars. Its length is 31 days.
November is the eleventh and penultimate month of the year in the Julian and Gregorian calendars. Its length is 30 days. November was the ninth month of the calendar of Romulus c. 750 BC. November retained its name when January and February were added to the Roman calendar. November is a month of late spring in the Southern Hemisphere and late autumn in the Northern Hemisphere. Therefore, November in the Southern Hemisphere is the seasonal equivalent of May in the Northern Hemisphere and vice versa. In Ancient Rome, Ludi Plebeii was held from November 4–17, Epulum Jovis was held on November 13 and Brumalia celebrations began on November 24. These dates do not correspond to the modern Gregorian calendar.
October is the tenth month of the year in the Julian and Gregorian calendars. Its length is 31 days. The eighth month in the old calendar of Romulus c. 750 BC, October retained its name after January and February were inserted into the calendar that had originally been created by the Romans. In Ancient Rome, one of three Mundus patet would take place on October 5, Meditrinalia October 11, Augustalia on October 12, October Horse on October 15, and Armilustrium on October 19. These dates do not correspond to the modern Gregorian calendar. Among the Anglo-Saxons, it was known as Winterfylleth (Ƿinterfylleþ), because at this full moon, winter was supposed to begin.
The Revised Julian calendar, or less formally the new calendar and also known as the Milanković calendar, is a calendar proposed in 1923 by the Serbian scientist Milutin Milanković as a more accurate alternative to both Julian and Gregorian calendars. At the time, the Julian calendar was still in use by all of the Eastern Orthodox Church and affiliated nations, while the Catholic and Protestant nations were using the Gregorian calendar. Thus, Milanković's aim was to discontinue the divergence between the naming of dates in Eastern and Western churches and nations. It was intended to replace the Julian calendar in Eastern Orthodox Churches and nations. From 1 March 1600 through 28 February 2800, the Revised Julian calendar aligns its dates with the Gregorian calendar, which had been proclaimed in 1582 by Pope Gregory XIII.
The Coptic calendar, also called the Alexandrian calendar, is a liturgical calendar used by the farming populace in Egypt and used by the Coptic Orthodox and Coptic Catholic churches. It was used for fiscal purposes in Egypt until the adoption of the Gregorian calendar on 11 September 1875. This calendar is based on the ancient Egyptian calendar. To avoid the calendar creep of the latter, a reform of the ancient Egyptian calendar was introduced at the time of Ptolemy III which consisted of adding an extra day every fourth year. However, this reform was opposed by the Egyptian priests, and the reform was not adopted until 25 BC, when the Roman Emperor Augustus imposed the Decree upon Egypt as its official calendar. To distinguish it from the Ancient Egyptian calendar, which remained in use by some astronomers until medieval times, this reformed calendar is known as the Coptic or Alexandrian calendar. Its years and months coincide with those of the Ethiopian calendar but have different numbers and names.
Adherents of Zoroastrianism use three distinct versions of traditional calendars for liturgical purposes. Those all derive from medieval Iranian calendars and ultimately are based on the Babylonian calendar as used in the Achaemenid empire. Qadimi ("ancient") is a traditional reckoning introduced in 1006. Shahanshahi ("imperial") is a calendar reconstructed from the 10th century text Denkard. Fasli is a term for a 1906 adaptation of the 11th century Jalali calendar following a proposal by Kharshedji Rustomji Cama made in the 1860s.
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.
Lists of holidays by various categorizations.
A birthday is the anniversary of the birth of a person, or figuratively of an institution. The birthdays of people are celebrated in numerous cultures, often with birthday gifts, birthday cards, a birthday party, or a rite of passage.
