Good question. I don't have a set amount of time between first and second drafts, but I have noticed that the longer it sits, the more errors/typos/plot issues become apparent. A good month or two gives plenty of distance. It helps to put the second draft aside to stew for a while as well. For me, this doesn't change with experience.
I actually looked this phenomenon up because inquiring minds want to know *winks*. It's called "change blindness":
The New York Times defined it as “the frequent inability of our visual system to detect alterations to something staring us straight in the face." ~BigThink.com
Anyway, it doesn't affect just writers, it affects everyone.
See? We're not so different after all!
How long do you shelve your first draft?
Does your "change blindness" get better with experience?