Would I get back to Los Angeles at day or night if I left Las Vegas at 1:30 in the afternoon?

You would arrive around 6 to 6:30 pm.

Direct Flights to LA are about 1 hour or less. Connecting flights would take some more time based on the connecting city.

IT WOULD STILL BE DAY AT THE LATEST WITH A DELAY IT WOULD STILL BE 3:30PM ENOUGH TIME LEFT IN THE DAY TO DO ALOT ENJOY

The flight is about one hour, you do the math

mostly night, also depends where in LA you're going, be aware of traffic.

It's a four to five hour drive.