In Judaism, a person who is shomer Shabbat or shomer Shabbos (plural shomré Shabbat or shomrei Shabbos; Hebrew: שומר שבת, "Sabbath observer", sometimes more specifically, "Saturday Sabbath observer") is a person who observes the mitzvot (commandments) associated with Judaism's Shabbat, or Sabbath, which begins at dusk on Friday and ends after sunset on Saturday.