What time do you consider the earliest that is "kosher" to get into your pajamas?

Or out of them? Do you ever stay in pajamas or a bathrobe all day? Would you open the door in your robe?

In other words, what is the etiquette of pajama wearing in your household?

(It’s 5:30 and I’m fighting the impulse to put on my robe but I know I’ll be in it by 7.)