Belief held by some Protestant Christians in
the strict observance of the Sabbath, Sunday,
following the fourth commandment of the
Bible. It began in the 17th century.
Sabbatarianism has taken various forms,
including an insistence on the Sabbath
lasting a full 24 hours; prohibiting sports
and games and the buying and selling of goods
on the Sabbath; and ignoring public holidays
when they fall on a Sunday.