To check if you are a Leap Second Pro user, follow these simple steps:
Look for the Pro button at the bottom of your screen. It has a star icon.
Tap the Pro button.
A screen will pop up confirming you are a Leap Second Pro user. On that same screen, you can Manage your Subscription and Restore a previously acquired Pro Subscription.
If you are using Leap Second on your tablet, iPad, or Android, you can trigger this screen by tapping the collaboration icon in the top right corner of the Calendar view.