US and IOA in one day OCT 3 or 5. Crowd calendar mistake?

We are doing both parks in one day, with 2 teens (13 and 15). Not staying in universal hotel.
Crowd calendar suggests Saturday oct 3 but it seems strange. Is it really better a saturday with Halloween Horror Night than monday oct 5?
Any suggestions? says its less crowded on Monday than Saturday. What world you do?

The sat has shorter hours due to HHN therefore there will be less day guests. For 2 parks in 1day I would personally go for the days with longest/latest park opening. Crowd diff of 1/2 points which is all it is doesn’t make that much difference but 2-3 extra park hours does. Are you getting exp pass and have you made a tp If you make a tp for the Sat then copy it and change date to the Monday you will be able to see diff in waits and what you can get done.