Despite the existence of standards, Calendar synchronisation is not easy.  I did once have a convoluted system that worked (sort of) but it fell apart when I switched away from using Google products.

Last night I was trying to work out why an old recurring calendar appointment from years ago was still popping up in the Windows 8.1 Calendar on my family PC.  It turned out to be quite simple: my outlook.com account was still subscribed to an old Google calendar that I don’t keep updated.  Unfortunately, what followed was about an hour of trying various solutions to get my calendars in sync again when I should really have been sleeping…

Removing old calendar subscriptions from outlook.com was fairly straightforward but I wanted to allow my work calendar (on Exchange) to be visible in Outlook.com (and hence on my family PC).  Access controls mean that a “pull” approach won’t work but, in the past, I’ve “pushed” a calendar using Outlook’s publish to a WebDAV server feature. When I had this working before (probably several PC rebuilds ago), I used a private URL for a Google calendar in the format  http://www.google.com/calendar/ical/user@domain.com/private-longstring/basic.ics but Outlook 2013 refused to use that location last night, telling me that “The address you typed is not valid. Check the address, and then try again.”

I could just maintain two calendars and overlay them in Outlook, but, whilst that will show me my personal and work appointments in a single view, it doesn’t help with free/busy time (i.e. stopping someone from booking an appointment with me at work when I’m not available to work). So my work calendar has to be the “master” and I simply sync it to another location so I can view it on other devices.

So, I set up an account with iCal Exchange (iCalShare is an alternative), creating a private calendar that Outlook was happy to publish to.  Result. Except it seems that outlook.com can only subscribe to calendars that are not password protected.  Meanwhile, Microsoft’s advice for sharing an Outlook calendar on Outlook.com would be better described as “export a point in time copy of an Outlook calendar to Outlook.com, and then share it”.

With my bed calling me, I set up a public calendar as a workaround but I’d rather keep my calendar private – even if I’m not sharing the full details of my appointments.  So, it looks like I’ll have to set up my own WebDav server (security by obscurity is not ideal either) just to publish from Outlook (connected to Exchange) to Outlook.com (and on to my family’s Windows 8.1 PC).

Incidentally, whilst working on this issue, I stumbled on an interesting post about “private” items in Outlook/Exchange – they may not be as private as you think!