When they need to- no schedule whatsoever.They eat & grow for a while until they need to shed. I agree it's hard to tell a shed cycle on white & very light color snakes, but it's likely his blood circulation that you're getting excited about- sorry.
For me, the best way to tell a shed is to look for milkiness in their eyes by using a small bright flashlight in a darkened room- don't shine directly, but from the side, across the arc of their eyes, & the cloudiness- if any- should be obvious that way.
Some young snakes might shed in 3-4 weeks, others take 2 months or longer. Might as well be watching paint dry.It's faster & more exciting.