Gregorian Calendar in the context of "Papal bull"

Christianity has been intricately intertwined with the history and formation of Western society. Throughout its long history, the Church has been a major source of social services like schooling and medical care; an inspiration for art, culture and philosophy; and an influential player in politics and religion. In various ways it has sought to affect Western attitudes towards vice and virtue in diverse fields. Festivals like Easter and Christmas are marked as public holidays; the Gregorian Calendar has been adopted internationally as the civil calendar; and the calendar itself is measured from an estimation of the date of Jesus's birth.

The cultural influence of the Church has been vast. Church scholars preserved literacy in Western Europe following the Fall of the Western Roman Empire. During the Middle Ages, the Church rose to replace the Roman Empire as the unifying force in Europe. The medieval cathedrals remain among the most iconic architectural feats produced by Western civilization. Many of Europe's universities were also founded by the church at that time. Many historians state that universities and cathedral schools were a continuation of the interest in learning promoted by monasteries. The university is generally regarded as an institution that has its origin in the Medieval Christian setting, born from Cathedral schools. Many scholars and historians attribute Christianity to having contributed to the rise of the Scientific Revolution.

The 3 September 1843 Revolution (Greek: Επανάσταση της 3ης Σεπτεμβρίου 1843; N.S. 15 September) was an uprising by the Hellenic Army in Athens, supported by large sections of the people, against the autocratic rule of King Otto. The rebels, led by veterans of the Greek War of Independence, demanded the granting of a constitution and the departure of the Bavarian officials that dominated the government. The revolution succeeded, ushering the period of constitutional monarchy (under the 1844 constitution) and universal suffrage in Greece.

The 31 March incident (Turkish: 31 Mart Vakası) was an uprising in the Ottoman Empire in April 1909, during the Second Constitutional Era. The incident broke out during the night of 30–31 Mart 1325 in Rumi calendar (GC 12–13 April 1909), thus named after 31 March where March is the equivalent to Rumi month Mart. Occurring soon after the 1908 Young Turk Revolution, in which the Committee of Union and Progress (CUP) had successfully restored the Constitution and ended the absolute rule of Sultan Abdul Hamid II (r. 1876–1909), it is sometimes referred to as an attempted countercoup or counterrevolution. It consisted of a general uprising against the CUP within Istanbul, largely led by reactionary groups, particularly Islamists opposed to the secularising influence of the CUP and supporters of absolutism, although liberal opponents of the CUP within the Liberty Party also played a lesser role. Eleven days later the uprising was suppressed and the former government restored when elements of the Ottoman Army sympathetic to the CUP formed an impromptu military force known as the Action Army (Hareket Ordusu). Upon entering Istanbul on 24 April Sultan Abdul Hamid II, accused by the CUP of complicity in the uprising, was deposed and the Ottoman National Assembly elevated his half-brother, Mehmed V, to the throne. Mahmud Shevket Pasha, the military general who had organised and led the Action Army, became the most influential figure in the restored constitutional system until his assassination in 1913.

The precise nature of events is uncertain; differing interpretations have been offered by historians, ranging from a spontaneous revolt of discontents to a secretly planned and coordinated counter-revolution against the CUP. Most modern studies disregard claims the sultan was actively involved in plotting the uprising, emphasising the CUP's mismanagement of troops in the build up to the mutiny and the role of conservative religious groups. The crisis was an important early moment in the empire's process of disintegration, setting a pattern of political instability which continued with military coups in 1912 and 1913. The temporary loss of power led to radicalisation within the CUP, resulting in an increasing willingness among Unionists to utilise violence. Some scholars have argued that the deterioration of ethnic relations and erosion of public institutions during 1908–1909 precipitated the Armenian genocide. The crisis also represented the demise of the Sultanate's power in the Ottoman Empire, as a series of constitutional amendments confined its function in government to the confirmation of parliamentary decisions, conversely cementing parliament's supremacy in a significant step of republicanism in Turkish political history.

January 1 is the first day of the calendar year in the Gregorian Calendar; 364 days remain until the end of the year (365 in leap years). This day is also known as New Year's Day since the day marks the beginning of the year.

The Serbs have many traditions. The Slava is an exclusive custom of the Serbs, each family has one patron saint that they venerate on their feast day. The Serbian Orthodox Church uses the traditional Julian Calendar, as per which Christmas Day (December 25) falls currently on January 7 of the Gregorian Calendar, thus the Serbs celebrate Christmas on January 7, shared with the Orthodox churches of Jerusalem, orthodox Macedonians, Russians, Georgians, and the Greek Old Calendarists.

Aloysius Lilius (c. 1510 – 1576), also variously referred to as Luigi Lilio or Luigi Giglio, was an Italian physician, astronomer, philosopher and chronologist, and also the "primary author" who provided the proposal that (after modifications) became the basis of the Gregorian Calendar reform of 1582.

The crater Lilius on the Moon is named after him, as is the asteroid 2346 Lilio. In computer science, the Lilian date is the number of days since the adoption of the Gregorian calendar on 15 October 1582.

Saint Tychon of Amathus (also Tychonas, Tikhon, Tycho) (d. 425) was the Bishop of Amathus on the island of Cyprus. He is venerated as a saint by both Catholic and Orthodox Christians. His feast day is June 29 on the Gregorian Calendar (equal to June 16 on the Julian calendar).

The village of Agios Tychonas, located near the ancient ruins of Amathus, is named after Saint Tychon.