'Appointed' in the Bible

the Jews established and adopted [it] for themselves and for their offspring, and for all who joined them. They did not neglect {to observe} these two days every year as it was written and appointed to them.

to establish these days of Purim at their appointed times, just as Mordecai the Jew and Queen Esther had imposed, and just as they had imposed on themselves and their offspring regulations of the fast and their lament.