The date module for Drupal (https://www.drupal.org/project/date) is generally brilliant and I've used it a number of times in the past. In Drupal 8 it is part of core which is testament to how useful a module it is.
However, I ran into an issue with the repeating date setting when using it for an event content type which was a bit of a pain to rectify. On my event I had set the date to "repeating" which in the input provides a variety of options to set the date to repeat. Its possible to set it to repeat every day, every week, every month or every year.
You can set what day(s) of the week, which occurrence of that day in the month, stop after so many occurrences or on a particular date. You can also set to include or exclude certain dates.
When I added, my only concern was whether it was too many options for a user to deal with, but it was all hidden until ticking the "repeat" box and so I decided it was okay. However, there is one big drawback, you cannot alter the time for the occurrence. It wasn't until an instance of this being required that I noticed the issue, but for me (in this installation anyway) it was a deal breaker.
So to resolve this, I wanted to switch to just allowing unlimited number of values. Unfortunately I couldn't just change it in the content type as there were many events already created. I also didn't want to have to edit the events. So I ended up creating a new content type with all the same fields except for the date. I created a new date field with no repeating option but unlimited values. I then had to edit all my views to include the new content type. Finally I redirected the links to create events to the new content type.
The transition has been very smooth and I feel better having it working correctly. The repeating date option might still be useful in some instances, but I guess only when time will always be the same or doesn't come into play at all.