I'm having this very issue. It seems to be related to the way local calendars are interacting with the Google Calendars, and I can't figure out how to make it stop. VERY annoying.
In the meantime:
-I've turned off CalDav (Exchange doesn't work with it either) and downloaded Calendars by Readle
-To get rid of the dupes en masse, I've turned on iCloud, merged the calendars, went into iCloud calendars and deleted all but one of the calendars so I can get rid of the dupes. Then, I created a new calendar and deleted the last remaining calendar. Hope that makes sense.
It's a terrible solution, but it's the best I've got for now.
Same here. So annoying. I'm syncing google calendars via Gmail as well as Facebook events on a 4S running iOS 6.
I'm now getting two, no wait four, no wait six..................well, duplicate versions of all birthdays, you get the idea.
Each of these duplicates is added to the main calender account.
The only workaround that I've found is to dump the standard calendar app and use CalAlarm or similar for calendar.
My iPad (iOS 5) has no such issues, nor does my wifes 3GS running iOS 6.
Same problem on 3GS. I use iCal to sync my gmail calendars. I have 22 birthday entries for each of my contacts now. :-( I loaded ios6 a while back, but the problem started yesterday when i said yes to integrating faceBook. I currently have FB uninstalled under settings and no contacts or calendar sync in there.
Couple more notes. I started seeing dupes again, but was able to get rid of them by saving settings in iphoneselect google web page. E.g. Uncheck and recheck birthday secondary calendar and press save. I was also able to recreate the problem by selecting the birthday calendar with the red package icon under iPhone calendars. Note that when I had the problem earlier this was NOT selected. Seems to be really flaky behavior with the calendar right now.
Ok, so after tinkering about here's the score:
Any five calendars selected, no issues
Any six calendars selected, major duplication of birthdays. These can be any six calendars. You don't even need any of them to be a birthday calendar or even the calendar into which the duplicates are being created!
I'll try deselecting and reselecting on the google web page and report back.
Here's what I did:
1. Go to http://www.google.com/calendar/iphoneselect and deselect all calendars.
2. Go to your iPhone calendar, select calendars at the top right and deselect all calendars.
3. Go to Settings>Mail, Contacts, Calendars>and then either GMail or Exchange (whichever you have enabled your calendar through.
4. Now turn off your calendar. You'll get a warning that everything will be deleted, but that's ok.
5. Now go back to the Google web page and select the calendars that you want to sync but don't select either of the ones to do with birthdays listed under Shared Calendars as your iPhone will generate these anyway.
6. Go back to your calender account settings on iPhone and turn calendar back on again.
7. Go back to your calendars on iPhone and select which ones you want to sync.
Et voila..........crazy duplicate birthdays gone :-)
The Google calendar iphone calendar sync settings is well-hidden. Don't know why this isn't visible in the calendar mobile setup page.
Following wizwilson's suggestion and unselecting "Contacts' birthdays and events" from the iphone select page seems to have done the trick.
Note: problem isn't solved. This is only a work-around. Either Google or Apple are at fault here and a fix is still required.
I confirm wizwilson's findings that you don't have to have a birthday calendar active to see the duplicates.
I added a few read-only shared calendars on the google iphone select screen (US Holidays and 4 sports team schedules). I started getting the duplicates for the sports teams (duplicates with more than 1 calendar).
Issue seems to be related to:
- GMail calendar
- Never (?) with the GMail primary calendar ("My Calendar")
- Happens only (?) with shared calendars AND if more than 4 (5?) calendars are selected in the iPhone calendar setup.
Have 3 calendars selected (iPhone Contacts Birthdays, GMail "My Calendar", GMail US Holidays") and am not seeing any duplicates. The "All GMail" calendar is also selected, but I didn't count that one. In the Google iphoneselect settings, I'm only selecting "My Calendar" and one shared calendar to sync with the iphone.