Esther 3:5-7

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.