I think newbie is a state of mind, rather than a time period. You're a newbie when you're still feeling your way, trying to suss out the rules, find your place.
Once you feel comfortable somewhere...that's when being a newbie ends.
LabRat
Athos: If you'd told us what you were doing, we might have been able to plan this properly. Aramis: Yes, sorry. Athos: No, no, by all means, let's keep things suicidal.