The American Church Dictionary and Cycopedia
Days of Obligation
These are days on which Communicants are bound
by the Faith they profess to be present at the celebration of the
Holy Communion and to rest as much as possible from servile work.
Such Days of Obligation are the following:
All Sundays in the year, not 12 but 52.
Christmas Day 25th December.
Feast of the Circumcision 1st January.
Feast of the Epiphany 6th January.
Annunciation Day 25th March.
Easter Day Movable.
Ascension Day Movable.
Whitsun Day Movable.
All Saints' day 1st November.
These files are public domain.
Miller, William James. Entry for 'Days of Obligation'. The American Church Dictionary and Cyclopedia. https://www.studylight.org/dictionaries/eng/acd/d/days-of-obligation.html. 1901.