It's for the subscription calendar only, not the regular calendars, Google, Samsung, family and work calendars will still be there. To find it, go to your calendar, then the menu on the left side and you'll see it at the bottom. I've never used it and didn't even know it was there until samsung gave a message of discontinuation.
It's for the subscription calendar only, not the regular calendar, go to your calendar and look at the bottom of the menu when you click the 3 lines on the left.
Generally when Samsung stops allowing an app to be used and shuts it down it's because it gets very little usage most people use the Google version or another version that they prefer