I joined Marriott rewards in September 2014. I will have accumulated 30 nights for the 2014 year (4 month period). Do these nights accrue for a 12 month period or do will I be starting over once 2015 arrives? I'm wondering because I am on pace for platinum level if they do accrue for the 12 months and if not it looks like I'll be starting from square one. Thanks for the help.