it's actually quite simple..I don't know how to explain it but here's an example:
If a clock was set to place on a number line, when you go counter clockwise you're going from left to right (or just right - either way it's still the same), the same of going to the right of 0 (which is positive).
If a clock was set to place on a number line, when you go clockwise you're going to the left, it's basically the same of going to the left of 0 which would give you negative numbers
