Sabbatarian

A person who observes Saturday as the Sabbath, as in Judaism, some Puritan groups, and some sect groups in Christianity such as Seventh Day Adventists. It also means a person who believes in a strict observance of the Sabbath, whether observed on Saturday or Sunday, including the OT prohibitions against work on the Sabbath. See Sabbath.

Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.