From the beginning, time was divided into weeks, each consisting of six days of working and one of rest (Gen. 2:2, 3; 7:10; 8:10, 12; 29:28). The references to this division of days becomes afterwards more frequent (Ex. 34:22; Lev. 12:5; Num. 28:26; Deut. 16:16; 2 Chr. 8:13; Jer. 5:24; Dan. 9:24-27; 10:2, 3). It has been found to exist among almost all nations.