I’m pretty sure that’s one of the sneaky things management does to people who don’t know better. You might want to check the Policy. It’s been awhile since I worked Saturdays and I had to fight many times for them to do the right thing. They finally just paid me and left me alone, when they realized how valuable I was doing the route I did every week. Lol.
It's OT for all time worked under the guarantee and straight time for the difference, as McFeely stated.
People Manual, section 3-5, table 3: Full-time employees receive 4 hours and part-time employees receive 2 hours at regular rate unless state law requires additional hours, in which case the Company follows state law.
It's right there in plain English, which means it will be completely misunderstood by some.