Many schools, universities and law courts had Easter terms. The fact that Easter was a moveable feast meant that one could not always tie the terms to the calendar nor have them be the same length every year. All schools were closed for Holy week preceding Easter and then most did not reopen until the Wednesday after Easter as Monday and Tuesday were holidays.
Many other dates were calculated as being so many days after Easter.
The names for the various terms aligned with the Church of England calendar, as did the court sessions.
The eight weeks after the Feast of St. Michael (September 29) was known as the Michaelmas term. It customarily started shortly after October 1.
At Oxford and at Dublin University, the Hilary Term, so named because the feast day of St Hilary of Poitiers (January 14) begins in January after Christmastide and runs to March. The Hiliary Term is usually 10 weeks in length and is determined by counting the number of Sundays following the feast day.
Five weeks after the Hiliary Term, the Trinity Term begins. It is 15 Sundays to 21 Sundays after the feast of St Hiliary, meaning it is six weeks in length. Trinity Sunday is the first Sunday after Pentecost. Pentecost is celebrated fifty days after Easter Sunday. The holy day is also called “White Sunday” or “Whitsunday” or “Whitsun,” especially in the United Kingdom.
To give you an idea about the School Terms, below are ones listed for the 1819 Terms of Schools
Hilary Term, ran from January 14 to April 3
Easter term, April 21 to May 26
Trinity Term, June 2 to July 19
Michaelmas Term, October 11 – December 17
Students were home between terms and from July 19 to October 11.
Hilary term, January 13 to April 2
Easter Term, April 21 to July 9
Michaelmas term, October 11 to December 16
Did not have a Trinity term and the Easter terms was longer.
Eton seemed to have called terms “halves”, though there were at least three of them in the school year. Eton terms basically followed this pattern:
September to two weeks before Christmas
Christmas holidays: a fortnight before and after Christmas
January to Palm Sunday.
Easter holidays were a fortnight from Palm Sunday.
For a more extensive list of school terms, check out Nancy Regency Researcher.