After framing, roofing, and putting up OSB, how long is it safe to leave standing, open to the weather, before covering with Tyvek?

OSB is a weather resistant board,it is made up of wood fibers and resin based glue,I have seen it unprotected for entire winters,although I would not do that myself,as soon as you can cover it up.

Thank you.

It is weather resistant to a point but how long do you plan to leave it without tar paper on the roof and tyvk on the walls? Rain isn't going to hurt you, but id not want to leave it out for months. The osb will soak up the water in time, after the waxy coating it has wears down.

Id just do it sooner than later

THEY both gave yiou good answers, but I have, When you hung the panels , DID YOU TURN THE Shining SIDE OUT?? THAT IS THE SIDE THAT IS SUSPOSED TO BE EXPOSED TO THE WEATHER F.B.E.