How do you use a watch as a compass?

Position your watch so that the hour hand points exactly to the sun. Divide the area between the hour hand and the number 12 in half with a match, the head of which points in the direction of due south.

[Principle]: As the Earth rotates, the sun "walks" around the Earth once every 24 hours. The hour hand of the watch will rotate twice on the dial. So in the morning we divide the distance from the hour hand to the number 12 in half, and in the afternoon we divide the distance from the number 12 to the hour hand in half. The match always points due south. And at 12 noon, both the hour hand and the number 12 point to the sun in the south.