Albert Barnes Commentary Esther 8:14

"So the posts that rode upon swift steeds that were used in the king`s service went out, being hastened and pressed on by the king`s commandment; and the decree was given out in Shushan the palace." — Esther 8:14 (ASV)

Being hastened - Between Sivan, the third month (June), when the messengers went out, and Adar, the twelfth month (March), when the struggle was to take place, the interval would be more than 8 months; but all haste was made to ensure there would be no misunderstanding.