I don't think I have the necessary hardware to capture the display and time it that way, so I was wondering if the mods are able to time it themselves. PS: I'm recording off my phone

Time runs the same that you would on a SNES or emulator. Timing starts on the frame mario appears (2.2 seconds after you click 1 player game) and ends when either the category says it ends, or on the frame that peach appears.

So, just use an external timer then? Sounds doable.

Yea, most people use the software "Livesplit"

Livesplit works really well that is what I use