I don't think a parent's work schedule should significantly obstruct his or her parental custody rights. Military personnel must follow those uncertain work schedules and there are ways to allocate custody in those situations.
Recall that his work also produces financial support. There is the risk that he could lose his job and there goes any reason to restrict his custody.

It is not. You will get hammered in court if you pursue this.

lana: If you can afford to, speak with a Family Lawyer, they are best when children are involved.