'Fixed' in the Bible

the Jews ordained and took upon them, and upon their seed, and upon all such as joined themselves to them, so that it should not fail, that they would observe these two days according to their writing and according to their fixed time, every year;

to confirm these days of Purim in their fixed times, according as Mordecai the Jew and queen Esther had enjoined them, and as they had decreed for themselves and for their seed, as to the matters of the fastings and their cry.