Esther 3:3-7

Then the palace officials at the king’s gate asked Mordecai, “Why are you disobeying the king’s command?” They spoke to him day after day, but still he refused to comply with the order. So they spoke to Haman about this to see if he would tolerate Mordecai’s conduct, since Mordecai had told them he was a Jew. When Haman saw that Mordecai would not bow down or show him respect, he was filled with rage. He had learned of Mordecai’s nationality, so he decided it was not enough to lay hands on Mordecai alone. Instead, he looked for a way to destroy all the Jews throughout the entire empire of Xerxes. So in the month of April, during the twelfth year of King Xerxes’ reign, lots were cast in Haman’s presence (the lots were called purim) to determine the best day and month to take action. And the day selected was March 7, nearly a year later.