New Living Translation
calling on them to celebrate an annual festival on these two days.

American Standard Version
to enjoin them that they should keep the fourteenth day of the month Adar, and the fifteenth day of the same, yearly,

Berean Study Bible
to establish among them an annual celebration on the fourteenth and fifteenth days of the month of Adar

Douay-Rheims Bible
21That they should receive the fourteenth and fifteenth day of the month Adar for holy days, and always at the return of the year should celebrate them with solemn honour:

English Revised Version
to enjoin them that they should keep the fourteenth day of the month Adar, and the fifteenth day of the same, yearly,

King James Bible
To stablish this among them, that they should keep the fourteenth day of the month Adar, and the fifteenth day of the same, yearly,

World English Bible
to enjoin them that they should keep the fourteenth and fifteenth days of the month Adar yearly,

Young's Literal Translation
to establish on them, to be keeping the fourteenth day of the month of Adar, and the fifteenth day of it, in every year and year,

Esther 9:21 Additional Translations ...