Many times, people have asked me why their calendars have multiple copies of their friends and family members birthdays. Usually, one of the multiples is indicated by a gift icon instead of a colored dot. This phenomenon is the result of Apple’s Birthday calendar, which automatically adds an entry in Calendar for any contact for whom a birthday has been added in the Contact card.
For example, my brother Paul’s birthday is November 22. So I remember to call him, I’ve manually added a calendar entry to November 22 to my personal calendar. Additionally, in his contact on my computer, I added his birthday. This is what the calendar looks like now.
On my phone, it looks like this:
Now I have a two versions of Paul’s Birthday in my calendar. To fix this, I can either delete the event I manually added (represented with a red dot next to it), I could delete Paul’s birthday from his contact card in the Address book, (shown below)
So, to fix the duplication, either delete manually added birthdays, delete birthdays from Contact Cards, or simply hide the “Birthdays” calendar in the Calendar app.