in the nine hundreds
Properly speaking, there is no "English" calendar system. You probably mean the predominant Western Calendar (also called the Christian Calendar). This calendar system is best called the "Gregorian Calendar", after Pope Gregory XIII who introduced the calendar system in 1582.
Christian Calendar Year 1727.
George Washington invented the lunar calendar
The name of the person that invented the first calendar is not known. The first calendar was invented in Scotland.
Easter Sunday comes after Good Friday in the Christian calendar.
622 AD in the Christian Calendar makes the Muslim year 1.
the amans use a christian calendar.
Advent
China
The Egyptian
AD is not used in the Jewish calendar. It is only used on the Gregorian (Christian) Calendar.