My husband (in the Air Force) says that you can request paternity leave once the baby is born, or you know it is being born (if it's scheduled, or once you go into labor). However, it is up to your husband's command when or if paternity leave is granted. The mission comes first. So, they will most likely give him paternity leave, but not necessarily when the baby is first born. Weird, I know.
You need to inform the command asap of when you are due, so that they can start preparing if need be. It will be up to YH's chain to decide how to handle the paternity leave, though as pp said, it may not be immediately. I've heard of most commands asking for a leave chit so they have something in writing. Then, when you actually go into labor/schedule delivery, you can inform them. Most commands will know in advance whether they can let YH take leave immediately. Just make sure to keep the lines of communication open!
If he is AF, he'll have 1 year to use the leave. That way if your family is coming out to help right after he won't have to take it right then so you both can have together time too.
IUD removed June '10. CP Sept'10.
Confirmed complete bicornuate uterus June '11.
Our guys are put on leave as soon as the baby comes. They just have to fill out the paper work, turn it in, and sign out. I feel really blessed our BN is on the ball in respect to that. They try super hard here to accommodate the families here. Once baby is born CMDRs and 1SGs go and visit. FRG visits too but I only do it once they are home. I remember being in the hospital and feeling tore up and people kept coming and coming. So I go once the family is adjusted and I can help answer any questions they may have.
Re: how/when do we request paternity leave?
"My 101 List - Updating asap, I swear!
I thought it was only 45 days? That's what MH was told when I had my son.