I was working in the reminders app last night and noticed that it failed to sync across all my devices, which run the latest version of OS X and iOS. I've tried to sign out of iCloud on my iOS devices but it keeps asking whether I want to delete the content from my iPhone and wasn't sure what to do.
IOS reminders app not syncing with Yosemite
reminders
Related Solutions
Yes you can. Just add your google account from System Preferences as usual. Then open iCal > Preferences > Accounts > iCloud and untick "Enable this account"
Quoting a solution I found in the Apple community web site:
I was having this problem. I changed the syncing range on the phone (under
Settings>Reminders) to syncAll Reminders. I then logged into iCloud and opened the Reminders tab. This actually caused the reminders on the phone to match the ones in iCloud. I then made changes on my phone while that tab was still opened and the changes started to appear in iCould (sometimes takes a few seconds - up to 20 or 30) and synched on my iPad as well. After that, all of my changes started to sync across all devices - iPhone, iPad,Mac and in iCloud, regardless of where I made the initial change.Hopefully this will work for you too.
Link here.
Best Answer
Try turning reminders in icloud off and back on. It might prompt for keeping the existing reminders locally when it is turned off in which case you can select
yes. When you turn it back on, it might ask for merging reminders and selectyesagain. This has worked for me in the past.