I don't get your question. Are you asking how long is a contract? First contract is 8 years. You can split it up active/inactive.
Are you talking about deployment? It varies.
Talk to a recruiter. People seem to think if you go into a recruiters office it means you sign a contract and swear in that day. It's not like that. Your first visit is just for your recruiter to get information about you and you to get information about what ever service you want to join.