To find out when your joining reward, birthday reward, special offer or reward you've purchased from the rewards store expires, simply navigate to "My Rewards" in your CravingCredits app. You can do this by following these steps:
Step 1: Open the app and tap "More" in the lower right corner of the home screen.
Step 2: Tap "My Rewards" from the menu that displays
Step 3: You'll see a tile displaying an image of each reward you've earned/been given, the name of the reward and when it expires.