'Appointed Time' in the Bible

the Jews established and made it a custom for themselves and for their descendants and for all who joined them, so that they would not fail to celebrate these two days as it was written and at the appointed time annually.

to establish these days of Purim [to be observed] at their appointed times, just as Mordecai the Jew and Queen Esther had established for them, and as they had established for themselves and for their descendants with instructions regarding their times of fasting and their lamentations (expressions of needing help).