I have had this same problem since June 14. MANY people are having this same problem. It is a glitch in the system. Only "repeated" events seem to be affected.
Either events do not repeat at all, or repeated events are stacked up all on the same day. The good news is that the original initially listed reminder is not deleted. Here is my solution.
Get a notebook and pencil. Search your Yahoo Calendar month by month by month, starting all the way back from the date you first started using Yahoo Calendar. In my case, that's May 2008.
As I mentioned, all the original initially listed reminders should still be there. Start writing down whatever reminders you need. Keep searching until the present day.
This is not a fix, obviously. But now you have your data written down. I will wait a week or so, and hopefully, Yahoo can repair the problem.
If not, I will have to switch to another, more reliable, Caledar system. I don't know, maybe Google.
I am having the same problem. Started searching for an answer and found your same question. Hoping if enough people share the frustration, the resolution will be swift.
I have been a faithful Yahoo "paying" customer for a number of years.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.