hmmm
if I understand

a 48 frames at 24 fps (film) it should be a 1.2 secs film.

then

if I want, lets say, a 2 mins animation I should use 2400 frames

is that true?

so

I suppose that instead of using playback end and end time at 48.00 I should use 2400.

Or,

instead of 48.00 in render globals I should type 2400?

which one is the one that I have to change?