Calendar Not Syncing

I'm in the same boat. I can easily create calendar items to the stock calendar, but they will not background sync to third party apps.

So, I wiped my iPhone clean and re-installed everything as a brand new iPhone. Everything is working fine now.

And then it suddenly stops again... for no reason. I did the same thing a couple of days ago, after updating to 2.0.1, and it fixed it... until today. Suddenly, my calendar still syncs... but it doesn't display on my apple watch's main watch face complication. ... but then it displays when you go into the calendar app...... and you can clearly see that while one event is "tentative" the one occurring in :45 minutes from the time I took those screenshots (3:15pm), is clearly occurring imminently, and is certainly an event happening today (amongst others). Oh and did I mentioned that I restarted both my apple watch and my iPhone (9.1).

Why have my apple products suddenly stopped "just working," these past few years? I'm not willing to go through the unpairing and repairing (not restoring because restoring will just perpetuate the problem) again with little hope that it will fix the problem again for more than a week.

Thank you so much. Your answer did the trick. Frustration gone.

Easy fix and it worked.

Thanks so much! This worked for me also. I had tried everything.

I have update my iPhone to version 9.2 (13C75) and my watch to version 2.1 (13S661) and the problem it is always present.

Very frustrating feature!

So, I woke this morning to discover that yet again the calendar sync issue has reared its ugly head yet again. The main display only shows an event for 7pm this evening from a calendar named "Duke Athletics" which is a shared calendar hosted on iCloud. That's great, save for the fact that my main schedule is on office365 through my school. This calendar has 5 events that are all displayed within the Calendar app once you click through to it via the complication on the main display. Great, so the information is present on the watch but isn't displayed. The one thing that has changed between yesterday and today, and been a consistent problem with Apple Watch calendars is invitations hosted through Microsoft's exchange server. Any time an invitation changes, the Apple Watch loses sync of the calendar necessitating a complete restore to factory default, then a restore to a preceding point when the calendar worked. This last point is critical, restoring to a point where the calendar had already lost sync, even when you unpair/repair the Watch appears to do nothing (in my four times having to do this in the PAST SIX MONTHS!!).

The feedback I got for pushing the button was seeing "No more events today" on my watch, until the re-sync started adding items back to the Watch's calendar.

Yeah, I've started following this troubleshooting procedure since it's happened a few times since my last post. 1) turn off iCloud calendar 2) restart Apple Watch and check if this resolved the issue 3) if not resolved, turn off exchange calendar (display in the calendar app, not remove the calendar from the device; this assumes you are mirroring your calendar to the apple watch) then turn off both apple watch and iPhone. 4) restart all and then re-enable the exchange calendar in the calendar app and after a few minutes it usually populates both the main calendar app and the complication on the apple watch. Not the idea solution but it appears there is a problem with how iCloud and Exchange handle calendar invites and changes to calendar events with invites. I wish this wasn't the case but it is clear after several WatchOS iterations that Apple hasn't been able to fix this issue reliably :-/

This solution worked for me in office 365 on a PC (iPhone 6 with OS 9.2.1):

Settings

Mail, Contact, Calendars, then second item from bottom: "Default Calendar"

Changed to "Calendar" under [my email] from "Calendar" under "ON MY IPHONE"

Thanks for that, Brian. Just sorted out my Watch for me. Ta.

Great post, thanks.

I just got an Apple Watch and had so much trouble getting my Google calendars to sync. I tried setting things up as a Google account, CalDAV, and also through alternative calendar apps. Nothing worked. I am convinced that this was all due to having access to too many calendars.

I was able to resolve this, however. I agree that the key is to link up a Google account that doesn't have a whole lot of calendars accessible to it. Not sure the limit exact, but less is more.

I have two main Google accounts: my work (where I am a Super Admin in Google Apps) and my personal account. I was trying to setup my work calendar for access. Being an admin, I have access to every user's calendar and Apple iCal was seeing this. I am pretty sure this was causing the connection to my watch to choke. Nothing was working.

My personal account is pretty clean, so I decided to try that one and it worked fine.

To get access to my work calendar, I (in Google) shared my work calendar to my personal Google account. Then back on my iPhone I included that calendar as one I wanted to download. It instantly showed up on my Apple Watch!!!

For me, I actually use the Google Mail and Calendar apps on my iPhone as my main apps. To make things work on the Apple Watch, I needed to setup Mail and iCal onto the device, but those are really just collecting the data in the background and slinging it over to my watch.

This suggestion from BrianFNH is the only one that consistently works for me. I'll explain more about "consistently" in a bit.

In the Apple Watch app, go to General -> Reset -> Reset Sync Data.

For the first 5 months of owning the Watch I never had a problem with syncing calendar events. When it first occurred, BrianFNH's suggestion solved the problem. Over the next 3 weeks the problem slowly came back...calendar events would sync but appear late. So, I have had to use BrianFNH's fix several times.

Related to this is the following. Sometimes, when I put the Watch on the charger in nightstand mode a green screen appears with the time and date. Other times, a large green battery condition screen appears. EVERY TIME I have Reset Sync Data, the large green battery screen appears when I put the watch on the charger. Then, over time, the large green battery screen does not appear and the large green date and time screen appears.

I think there is a bug in Watch OS with regard to all this. Shoudn't have to clear out all sync data on a regular basis to have the Watch function correctly.