Maundy Thursday uses the term "Maundy Thursday" to refer to the holy day in its official sources. In the Eastern Orthodox Church, the name for the holy day is, in the Byzantine Rite, "Great and Holy Thursday" or "Holy Thursday", and in Western Rite Orthodoxy "Maundy Thursday", "Holy Thursday" or both. The Coptic Orthodox Church uses the term "Covenant Thursday" or "Thursday of the Covenant". In the Maronite Church and the Syriac Orthodox Church, the name is "Thursday of Mysteries". "Maundy Thursday" is the official name of the day in the civil legislation of England and the Philippines. The day has also
Perennial calendar by Auguste Comte (1849); and the International Fixed Calendar, by Moses B. Cotsworth (1902), and championed by George Eastman. Blank-day reform proposals face a religious objection, however. Sabbatarians, who are obliged to regard every seventh day as a day of rest and worship, must observe their holy day on a different weekday each year. Leap week calendar plans often restrict common years to 364 days, or 52 weeks, and expand leap years to 371 days, or 53 weeks. The added week may extend an existing month, or it may stand alone as an inserted seven-day month. The leap-week calendar may