What is Matt to do each day and why?

Matt makes a notch on a stick everyday, in order to keep track of how long his family has been gone, and how soon they would return. He uses a new stick each week. His father told him that shen he got to the seventh stick.... he should start looking for their arrival.

His father thought he would be gone six weeks. He told Matt to keep track by making a notch on a stick every day. When he had seven notches, he was to use a new stick. ”When you get to the seventh stick, start looking for us,” said his dad.