It's shown to be night time when the outside of Jerry's (Jerry Seinfeld) building is shown and Jerry & Claire (Sarah Peterson) are going to sleep. Then when Darin (Jarrad Paul) and Kramer (Michael Richards) are inside Jerry's apartment during his fight with Claire, Darren yells to Kramer that the NYU dean is on the phone. The dean would not be calling a business office (Kramerica) during the night.
George's (Jason Alexander) boss tells him that he saw him carrying the 200 lbs motorised scooter with one hand yet in episode 9.1,The Butter Shave (1997) we see George running & carrying the scooter with both hands when he runs into his boss.
Jerry says he "put a six-hour tape in" towards the end when Kramer is doing his experiment. The only type of video tape capable of recording six hours is VHS (at the slowest speed for a normal 2-hour tape), and Jerry's camera is too small to be VHS (it is likely 8mm - 4 hours maximum).
Despite the fact that George deserved everything he got the way Play Now treated George was criminal. Also, despite being under a contract, George can be let go if he doesn't fulfill his end of the contract which involves doing all his duties which he obviously wasn't doing.
Jerry (Jerry Seinfeld) says he's throwing away his belt because it hit the urinal as he unbuckled it. It's not necessary to unbuckle a belt to use the urinal though.