'Appointed Time' in the Bible

the Jews established and made a custom for themselves and for their descendants and for all those who allied themselves with them, so that they would not fail to celebrate these two days according to their regulation and according to their appointed time annually.

to establish these days of Purim at their appointed times, just as Mordecai the Jew and Queen Esther had established for them, and just as they had established for themselves and for their descendants with instructions for their times of fasting and their lamentations.