Mat Matthew, chapter The Gospel According to Matthew, chapter 2
When Herod realized he'd been fooled by the wise men, he got very angry. He sent men to kill all the young boys in Bethlehem and the regions nearby who were two years old and under. This was based on the time frame he'd discovered from the wise men.2:16. In other words, it had been up to two years previously that the star had first appeared to the wise men.