Fixed prayer times

Fixed prayer times, praying at dedicated times during the day, are common practice in major world religions such as Judaism, Christianity, and Islam.
Judaism.
Jewish law requires Jews to pray thrice a day; the morning prayer is known as Shacharit, the afternoon prayer is known as Mincha, and the evening prayer is known as Maariv. According to Jewish tradition, the prophet Abraham introduced Shacharit, the prophet Isaac introduced Mincha, and the prophet Jacob introduced Maariv. Jews historically prayed in the direction of the Temple of Solomon in Jerusalem, where the "presence of the transcendent God ("shekinah") [resided] in the Holy of Holies of the Temple". In the Bible, it is written that when the prophet Daniel was in Babylon, he "went to his house where he had windows in his upper chamber open to Jerusalem; and he got down upon his knees three times a day and prayed and gave thanks before his God, as he had done previously" (cf. ). After its destruction, Jews continue to pray facing Jerusalem in hope for the coming of the Messiah whom they await.
Christianity.
From the time of the early Church, the practice of seven fixed prayer times have been taught. In "Apostolic Tradition", Hippolytus instructed Christians to pray seven times a day, "on rising, at the lighting of the evening lamp, at bedtime, at midnight" and "the third, sixth and ninth hours of the day, being hours associated with Christ's Passion." Christians attended the liturgy on the Lord's Day, worshipping communally in both the morning and evening. They prayed privately throughout the rest of the week, with the exception of Christian monastics who gathered for prayer corporately. This practice of seven fixed prayer times was done in the bodily positions of prostration and standing, which continues today in some Christian denominations, especially those of Oriental Christianity.
Oriental Orthodox Christians (such as Copts and Indians), as well as members of the Mar Thoma Syrian Church (an Oriental Protestant denomination), use a breviary such as the Agpeya and Shehimo to pray the canonical hours seven times a day while facing in the eastward direction, in anticipation of the Second Coming of Jesus; this Christian practice has its roots in , in which the prophet David prays to God seven times a day. In the Indian Christian and Syriac Christian tradition, these canonical hours are known as Vespers (Ramsho [6 pm]), Compline (Soutoro [9 pm]), Nocturns (Lilio [12 am]), Matins (Sapro [6 am]), third hour prayer (Tloth sho`in [9 am]), sixth hour prayer (Sheth sho`in [12 pm]), and ninth hour prayer (Tsha' sho`in [3 pm]). In the Coptic Christian and Ethiopian Christian tradition, these seven canonical hours are known as the First Hour (Prime [6 am]), the Third Hour (Terce [9 am]), the Sixth Hour (Sext [12 pm]), the Ninth Hour (None [3 pm]), the Eleventh Hour (Vespers [6 pm]), the Twelfth Hour (Compline [9 pm]), and the Midnight office [12 am]; monastics pray an additional hour known as the Veil. Church bells are tolled at these hours to enjoin the faithful to Christian prayer. Those who are unable to pray canonical hour of a certain fixed prayer time may recite the "Qauma", in the Indian Orthodox tradition. 
In Western Christianity and Eastern Orthodox Christianity, the practice of praying the canonical hours at fixed prayer times became mainly observed by monastics and clergy, though today, the Catholic Church encourages the laity to pray the Liturgy of the Hours and in the Lutheran Churches and Anglican Communion, breviaries such as The Brotherhood Prayer Book and the Anglican Breviary, respectively, are used to pray the Daily Office; the Methodist tradition has emphasized the praying of the canonical hours as an "essential practice" in being a disciple of Jesus.
Many Christians have historically hung a Christian cross the eastern wall of their houses, which they face during these seven fixed prayer times. Before praying, Oriental Orthodox Christians and Oriental Protestant Christians wash their hands, face and feet in order to be clean before and present their best to God; shoes are removed in order to acknowledge that one is offering prayer before a holy God. In these Christian denominations, and in many others as well, it is customary for women to wear a Christian headcovering when praying.
Islam.
Muslims pray five times a day, with their prayers being known as Fajr (dawn), Dhuhr (after midday), Asr (afternoon), Maghrib (sunset), Isha (nighttime), facing towards Mecca. The direction of prayer is called the qibla; the early Muslims initially prayed in the direction of Jerusalem before this was changed to Mecca in 624 CE, about a year after Muhammad's migration to Medina.
The timing of the five prayers are fixed intervals defined by daily astronomical phenomena. For example, the Maghrib prayer can be performed at any time after sunset and before the disappearance of the red twilight from the west. In a mosque, the muezzin broadcasts the call to prayer at the beginning of each interval. Because the start and end times for prayers are related to the solar diurnal motion, they vary throughout the year and depend on the local latitude and longitude when expressed in local time. In modern times, various religious or scientific agencies in Muslim countries produce annual prayer timetables for each locality, and electronic clocks capable of calculating local prayer times have been created. In the past, some mosques employed astronomers called the "muwaqqit"s who were responsible for regulating the prayer time using mathematical astronomy.
The five intervals were defined by Muslim authorities in the decades after the death of Muhammad in 632, based on the hadith (the reported sayings and actions) of the Islamic prophet. According to Justin Paul Heinz, the five fixed prayer times in Islamic prayer were likely influenced by the canonical hours of Oriental Orthodox Christians (who were regarded as Monophysites) in the 4th century who prayed seven times a day, given the extensive contact that Muhammad and his companions had with Syrian Christian monks. Abu Bakr and other early followers of Muhammad were exposed to these fixed times of prayer of the Syrian Christians in Abyssinia and likely relayed their observations to Muhammad, "placing the potential for Christian influence directly within the Prophet’s circle of followers and leaders."