How Long Does Majuana Stay In Your System If You Only Smoke 5 Or 6 Times A Month?

I think it depends with what kinds of testing you could have.
I know by checking the hair follicles from your head, they can tell up to 1 year

Some say 30 days but if the person just stops then they wouldn't have to worry about failing a test and could save some money.

if your taking a urine test it will show in your system up to 30 days, if they check your hair it can show up to a couple years because they don't usually take it from your head especially if you a guy they'll take it from your armpit, chest, legs, or arms

Drugs (other than alcohol) can be retained in the system much longer by the chronic-user after their last use.  For instance, Marijuana stay in your system for 2-5 days (the daily, heavy user can sometimes be detected up to 30+ days).