Timed hits are here from the Mario & Luigi Series on a select moves that are listed in the description of this mod. Here is how to perform them and what they do

Timed hits are performed by press the A or B button (depending on the active bro) right before the hitbox comes out. Successfully performing one will change the text over your head from "Ok!" to "Excellent!" and improving the moves damage and knockback.

In regards to the buttons that must be pressed, if you are Mario, the input is A. If you are Luigi, the input is B. When doing down air, the input visual is slightly late, so press before that. After the first bounce on Luigi's down air you can just chain bounces with dair instead of pressing the B button again.