Many months....
I think it took 6 or 7 months to name my male Russian.
It took 5 months to name my 2 adopted leopards.
Even now I'm still not hip on most of their names and want to change them... (my 4 yr old helped name them) but I don't really "use" their names anyway.
My wife come up with all their name within minutes. But she will change them from time to time, I will be in trouble if I call a wrong or old name of one of the tortoise. It is OK, As long as she is happy.
My personal pets get named pretty quickly, but my fosters....new policy here...no naming...cuz once you do, you get more attached and Sandy has trouble letting torts go! I'd have far more than 17 otherwise. [GRINNING FACE WITH SMILING EYES][PURPLE HEART]
It took me a couple of months and a name change before realizing my RF's name is Skeletor. Glad to know I'm not the only one that had trouble. My girlfriend thought I was crazy for taking so long.