From day 1 keep an official FAA compliant civilian logbook during your military time, then you log EACH your military flights and civilian flights same as you would civiluan time (including taxi time). Then your logbook is your "official" flight time. That is the best way to do it. then you would just need to show your checkride/ aircraft rating forms from your military records (This serves as Endorsementds in your logbook) along with your official signed-by-you log book.