havin a big discussion at my gym about the roman deadlift.... Half of us say do it on back day and half on leg day..... Which is better 2 do it on? reasoning?

It is a glute ham exercise with some low back involvement. Make sure you drive your ass out hard and keep your back arched.

i do it on leg day because it hammers the hams. I generally do back on mon, and legs on fri. It does get a bit of work in lower back, but not as much as full deads. The way i do them is push my butt back to lower the weight, instead of "bending at the waist". To come up, I focus on pushing hips forward, which will raise the torso, and squeeze glutes hard at top. I get a little pump in lower back like I said, but I don't focus the work there.

http://www.bodybuilding.com/fun/issa63.htm

Its more about stabilizing the lower back but it is primarily for hamstrings and glutes like previously mentioned... LEG DAY is the winner... definitely

Leg day.

I'd say either, but would call them squat day and dl day... take into account if you are doing any other hammy/glute exercises and on which day.

Do you mean Romanian deadlift? (the two words are not interchangeable)