How can i check if a time window is in another time window

I need a function in PHP where i can check if a time window is in another time window. I have tried a lot of stuff but i dont get it.

for example: Time window 1: 12:00 - 13:00 Time window 2: 12:15 - 13:30

How can i check that time window 2 is in time wondow 1?