'Duty' in the Bible

even as the duty of every day required, offering according to the commandment of Moses, on the sabbaths, and on the new moons, and on the set feasts, three times in the year, even in the feast of unleavened bread, and in the feast of weeks, and in the feast of tabernacles.

And he appointed, according to the ordinance of David his father, the courses of the priests to their service, and the Levites to their offices, to praise, and to minister before the priests, as the duty of every day required; the doorkeepers also by their courses at every gate: for so had David the man of God commanded.

besides them that were reckoned by genealogy of males, from three years old and upward, even every one that entered into the house of Jehovah, as the duty of every day required, for their service in their offices according to their courses;