According to the Jewish calendar, the first day of the week is Sunday. And that makes the 7th day, which is Saturday, the Sabbath day. It begins in the sunset of Friday and ends in the nightfall (after the sunset where everything is already dark) of Saturday. The week consists of seven days, distinguished from one another by their place in the week. They are called the first day, the second day, the third day, and so on to the seventh day, which is besides called "Shabbat" (Rest) or "Yom ha-Shabbat" (Day of Rest). As the Sabbath is the most important day of the week, the term "Shabbat" denotes also "week"—that is, the period from one Sabbath to the next; and a year of rest is also called "Shabbat" (or "shabu'a"). Friday, as the forerunner of Shabbat, is called "'Ereb Shabbat" (The Eve of Sabbath). The term "'ereb" admits of two meanings: "evening" and "admixture" (Ex. xii. 38...