Coptic calendar in the context of "Thout"

A calendar era is the period of time elapsed since one epoch of a calendar and, if it exists, before the next one. For example, the current year is numbered 2025 in the Gregorian calendar, which numbers its years in the Western Christian era (the Coptic Orthodox and Ethiopian Orthodox churches have their own Christian eras).

In antiquity, regnal years were counted from the accession of a monarch. This makes the chronology of the ancient Near East very difficult to reconstruct, based on disparate and scattered king lists, such as the Sumerian King List and the Babylonian Canon of Kings. In East Asia, reckoning by era names chosen by ruling monarchs ceased in the 20th century except for Japan, where they are still used.

The ancient Egyptian calendar – a civil calendar – was a solar calendar with a 365-day year. The year consisted of three seasons of 120 days each, plus an intercalary month of five epagomenal days treated as outside of the year proper. Each season was divided into four months of 30 days. These twelve months were initially numbered within each season but came to also be known by the names of their principal festivals. Each month was divided into three 10-day periods known as decans or decades. It has been suggested that during the Nineteenth Dynasty and the Twentieth Dynasty the last two days of each decan were usually treated as a kind of weekend for the royal craftsmen, with royal artisans free from work.

Because this calendrical year was nearly a quarter of a day shorter than the solar year, the Egyptian calendar lost about one day every four years relative to the Julian calendar. It is therefore sometimes referred to as the wandering year (Latin: annus vagus), as its months rotated about one day through the solar year every four years. Ptolemy III's Canopus Decree attempted to correct this through the introduction of a sixth epagomenal day every four years but the proposal was resisted by the Egyptian priests and people and abandoned until the decree by Augustus in 25 BC that established the Alexandrian or Coptic calendar. The introduction of a leap day to the Egyptian calendar made it equivalent to the Julian calendar, although (like the latter) it continues to diverge from the Gregorian calendar at the turn of most centuries.

The Ethiopian calendar (Amharic: ዐውደ ወር; Ge'ez: ዐውደ ወርኅ; Tigrinya: ዓዉደ ኣዋርሕ), or Geʽez calendar (Geʽez: ዐውደ ወርኅ; Tigrinya: ዓዉደ ኣዋርሕ, Amharic: የኢትዮጲያ ዘመን አቆጣጠር) is the official state civil calendar of Ethiopia and serves as an unofficial customary cultural calendar in Eritrea, and among Ethiopians and Eritreans in the diaspora. It is also an ecclesiastical calendar for Ethiopian Christians and Eritrean Christians belonging to the Orthodox Tewahedo Churches (Ethiopian Orthodox Tewahedo Church and Eritrean Orthodox Tewahedo Church), Eastern Catholic Churches (Eritrean Catholic Church and Ethiopian Catholic Church), and Protestant Christian P'ent'ay (Ethiopian-Eritrean Evangelical) Churches. The Ethiopian calendar is a solar calendar that has much in common with the Coptic calendar of the Coptic Orthodox Church of Alexandria and Coptic Catholic Church, but like the Julian calendar, it adds a leap day every four years without exception, and begins the year on 11 or 12th of September in the Gregorian calendar (from 1900 to 2099). Its epoch (first day of first year) equates to 29 August 8 AD. The neighbouring Coptic calendar is very similar to the Ethiopian calendar, except that it has a different epoch (29 August, 284 AD) and different names for the days of the week and months of the year.

The Ethiopian calendar has twelve months, all thirty days long, and five or six epagomenal days, which form a thirteenth month. The Ethiopian months begin on the same days as those of the Coptic calendar, but their names are in Geʽez. A sixth epagomenal day is added every four years, without exception, on 29 August of the Julian calendar, six months before the corresponding Julian leap day. Thus, the first day of the Ethiopian calendar year, 1 Mäskäräm, for years between 1900 and 2099 (inclusive), is usually 11 September (Gregorian). It falls on 12 September in years before the Gregorian leap year, however.

The Feast of the Holy Cross, Feast of the Exaltation of the Holy Cross, or Feast of the Cross, commemorates the True Cross. On 13 September, 335, the Constantinian Basilica over the Holy Sepulchre was consecrated in Jerusalem. The day after the church's consecration, the relic of the cross was shown ("exalted") for the first time to the people for veneration. Later, the feast was also associated with the commemoration of the recovery of the Holy Cross by emperor Heraclius on 13 September 628.

In the liturgical year, there are several celebrations which honor and celebrate the cross used in the crucifixion. Unlike Good Friday, which is dedicated to the passion of Christ and the crucifixion, these feast days celebrate the Cross itself, as the sign of salvation. It is celebrated by Catholics (Latin Church Catholics, Eastern Catholics), Eastern Orthodox, Oriental Orthodox, Church of the East, Old Catholics, Lutherans and Anglicans, and to a lesser extent by Presbyterians, Methodists and Baptists. The most common day of commemoration is September 14 for churches that use the Gregorian calendar and September 27 for churches that use the Julian calendar, Ge'ez calendar, or Coptic calendar.

Hathor (Coptic: Ϩⲁⲑⲱⲣ, Hathōr), also known as Athyr (Ancient Greek: Ἀθύρ, Athýr) and Hatur (Arabic: هاتور), is the third month of the ancient Egyptian and Coptic calendars. It lies between November 10 and December 9 of the Gregorian calendar.

The month of Hathor is also the third month of the season of Akhet (Inundation) in Ancient Egypt, when the Nile floods historically covered the land of Egypt; they have not done so since the construction of the High Dam at Aswan.

The Season of the Harvest or Low Water was the third and final season of the lunar and civil Egyptian calendars. It fell after the Season of the Emergence (Prt) and before the spiritually dangerous intercalary month (Ḥryw Rnpt), after which the New Year's festivities began the Season of the Inundation (Ꜣḫt). In the Coptic and Egyptian calendars this season begins at the start of the month of Pashons (about 9 May), continues through the months of Paoni and Epip, before concluding at the end of Mesori (about 5 September).

The festival known as Sham Ennessim, is often claimed to have originated from Shemu. Sham Ennessim is an official holiday in modern Egypt. Earlier Egyptian šm.w and its Coptic successor ϣⲱⲙ relate to the name of a season in Egyptian, not a specific festival.

Pope Tawadros II (born Wajih Subhi Baqi Sulayman; 4 November 1952) is the 118th and current Pope of Alexandria and Patriarch of the See of St. Mark, succeeding the late Pope Shenouda III as leader of the Coptic Orthodox Church of Alexandria. He took office on 18 November 2012 (Coptic calendar: 9 Hathor 1729), two weeks after being selected.