Snippet from the wordpress.org thread:
"So I created an event and checked the Repeat box. Then I choose Custom and select my various dates and everything works great.
The problem is, when I edit that event, and click on the dates to bring up the Custom calendar interface... all my dates are there, but they're all one day off. So if the custom dates listed are January 5, 7, and 9, when I click to bring up the custom calendar, the dates that are highlighted are January 4, 6 and 8.
It makes editing a royal pain. If I have 15 dates for that repeating event and need to delete 1, I first have to move all 15 dates forward one day before I can edit. Is there a way to fix this??"