The Division of Priestly Labor: 24 Shifts

The cohanim who were responsible for the daily service in the Holy Temple were divided into 24 separate shifts. These groups were made up of men who hailed from all parts of the land; the duration of each shift's duties was for 1 week. During that week, each respective shift would be entirely responsible to carry out all of the daily functions in the Temple. Thus, the priests took turns throughout the year in a manner that can be compared to military reserve duty - one would come to Jerusalem for his obligatory period of service in the Temple.