public static int getCurrentDay(Game game)
throws InvalidDateException{
DateTime startDate = new DateTime(game.getVirtualStartDate().getTime());
DateTime currentDate = new DateTime(game.getVirtualCurrentDate().getTime());
if (startDate.isAfter(currentDate))
throw new InvalidDateException("Virtual start date cannot be after virtual current date.");
// got from
// http://stackoverflow.com/questions/3802893/number-of-days-between-two-dates-in-joda-time
int diff = Days.daysBetween(startDate.toDateMidnight(),
currentDate.toDateMidnight()).getDays();