Maundy Thursday April 22 inclusive, but these dates fall on different days depending on whether the Gregorian calendar or Julian calendar is used liturgically. Eastern churches generally use the Julian calendar and celebrate this feast throughout the 21st century between April 1 and May 5 in the more commonly used Gregorian calendar. The liturgy held on the evening of Maundy Thursday initiates the Easter Triduum, the period which commemorates the passion, death, and resurrection of Jesus; this period includes Good Friday and Holy Saturday, and ends on the evening of Easter. The Mass of the Lord's Supper or service of worship is
Armelin's calendar Armelin's calendar Armelin's calendar was developed around 1887 by French astronomer Gustave Armelin, who developed a twelve-month calendar in which the year of 364 days was divided into four equal quarters of 91 days. Armelin's calendar proposal was discussed chiefly under the auspices of the Société astronomique de France in 1887 and recently in the French Academy of Sciences. The advantages of this simple system are evident. The months are nearly equal in length, and all have the same number of business days. Any given day of any month falls on the same day of the week each year. A