The dates for Contramid have been consistent for at least the past 3-4 years. I researched the dates last year to coordinate my DD wedding and DS summer cruse possible commitment. We picked dates between West and East and got lucky. It is possible to request east or west, and it may be granted with a compelling reason, but as always, the needs of the Navy will come first and the dates are always subject to change. The dates will not be published until January / February and your DD/DS specific orders could be issued only a week or a few days before they need to depart.