This is my first year with a brumating tortoise (i had sulcatas and leopards prior), so, I plan on around late Febraary into March just having fresh food in there for him/her daily. From what I have researched, it seems on average, they come out slowly, kinda like they do when they get ready to brumate. They come out for a couple hours in the warmest part of the day, then back in, and each day is a little longer, little longer, until they are comfortable with the warmer weather to be out most of the day.