how long should i veg

i just got started and im growing 9 reg plants, how long should i veg them? my friend says i should do it for like 4 weeks but i think that is a little long

it depends on what you want from the plants. If you are interested in keeping them small size/yield, 4 weeks is good. If you want better yeilds 5-6 weeks is good. If you have the time and space you can veg as long as you want.

Edit: my reply is assuming you mean growth from seed to 12/12.

ok i just wasnt sure if i could like over veg them or something

Around 4 weeks is best but people say that the longer you vegg the more bud you get .
but like you know its not appoved