Yes. In Configuration > Order: Subscription set Subscription Meals To Choose Reminder - days before delivery date cutoff (in days) (default 3). A scheduled job then emails every subscriber who still has unselected meals for an upcoming date that many days before that date's cut-off, using the Subscription: Meals To Choose Reminder email/marketing trigger. The message includes the delivery date, how many meals are left to choose, the days left, and the cut-off day and time. Each subscription/date pair is reminded once.