'Duty' in the Bible

He ordered them, "This is what you must do. One third of the unit that is on duty during the Sabbath will guard the royal palace.

The two units who are off duty on the Sabbath will guard the Lord's temple and protect the king.

The officers of the units of hundreds did just as Jehoiada the priest ordered. Each of them took his men, those who were on duty during the Sabbath as well as those who were off duty on the Sabbath, and reported to Jehoiada the priest.