Last year, I wrote a very long blog post on the problems I was having with calendar synchronisation but I never reached the point where I was ready to publish it. Almost a year on, and I finally have something that’s working well for me but, as it’s such a long story, I’ve tidied up the original post and published it (for the full history) and I’ll write a new one here that describes the working scenario.

Calendar synchronisation… shouldn’t it all be a bit easier than this?

First up – to recap on the original problems:

• Due to limitations with Microsoft Office’s Online calendar functionality. I was synchronising local calendars at home and work, using Google Calendar (GCal) as an intermediary.
• The main problem was synchronisation between Outlook 2007 and GCal and, after trying a huge list of products, each of which nearly worked, but not quite, I got it working using CompanionLink for Google; however the various other products I’d used along the way had left me with duplicate and missing calendar entries – and a sour taste in my mouth.
• On the Mac at home, Apple iCal was working with GCal but there were still some issues around synchronisation with a local Exchange Server via Entourage.

Back to the drawing board

After having implemented Google Apps for my home/small business IT, I decided to have another go at calendar synchronisation.

This time, to minimise the scope for synchronisation errors, rather than merging my work calendar into my home calendar, I decided to set up another Google Calendar to mirror the Exchange one I use for work. In addition, the process was simplified as Google now has a synchronisation product (Google Calendar Sync) which can handle the Exchange/Outlook-Google side of things and I am no longer using Entourage or Exchange Server at home.

The whole thing looks something like this:

As can be seen in the diagram, I actually have three calendars:

1. My work calendar exists on a corporate Microsoft Exchange server (accessible via Outlook Web Access but primarily used with Outlook).
2. I’ve also created a Google Calendar to hold a copy of this “work” calendar in the cloud and Google Calendar Sync does the magic to keep the two in sync.
3. Finally, there’s my “personal” calendar, which lives at Google Apps.

Google Calendar sync is set up for a 2-way sync and, even though I can synchronise as frequently as every 10 minutes, Outlook performance suffers whilst the sync is taking place so I have it set to synchronise hourly. The main drawbacks with this approach are: the need for a client helper application; the 1:1 nature of the synchronisation (i.e. you cannot sync with multiple calendars); and the inability to set synchronisation schedules (or even to control the date range for synchronisation) – on the other hand, it’s free.

In Google Calendar, I have given my Google Apps account access to my “work” calendar, which means that I have full read-write access to it from anywhere that I use Google Apps. That access could be via a browser, of using native applications on my iPhone, MacBook, or another device (e.g. a Windows PC). Basically, my work calendar is visible everywhere.

My “personal” calendar is… personal. I can access it directly from any of the devices that I use for accessing Google Apps but I don’t want my colleagues to know that I have certain appointments and one thing I found with the Google Calendar Sync (luckily I spotted it early) was that appointments marked as private in Outlook were visible once they got to Google Calendar. I still need to think about how to pass my personal free/busy information back to Outlook/Exchange at work but, for now, my “personal” calendar exists in Google Apps and is visible in my “work” Google Calendar account but I don’t sync it back to Outlook. Basically, if I look at Outlook, I see work appointments but if I open a browser and got to the Google Calendar, I can see work and personal information.

What does it all look like?

In this screen-shot of Outlook 2007 connected to my corporate Exchange Server, my “work” calendar is visible but there are no appointments from my “personal” calendar:

Viewing either of the Google calendars in a browser (in this case it’s Safari on a Mac) shows my “work” and “personal” calendars using different colours:

I can also subscribe to these calendars using the iCalendar protocol from Apple iCal, Windows Calendar (or another desktop client):

On the iPhone, I can use either the built in calendar application or a browser application (I prefer the browser version as the iPhone Calendar assigns different colours to the various calendars):

You may notice that I also subscribe to a public calendar which provides the details of UK public holidays. Doing this means that the public holidays show up in my calendar using a different colour to the other calendars but there are other calendars that I could subscribe to – for instance sports calendars (e.g. the Northampton Saints fixture list) – or anything that uses the iCalendar format described in RFC 2445.

Summary and other points of note

In all, this solution seems to be working remarkably well for me and provides a suitable level of abstraction between work and personal calendar details whilst still letting me (and my family – or anyone else that I share my calendars with) see everything that I’m up to. I still need to work on getting personal free/busy details to populate my “work” calendar but, other than that, I’m pretty happy with the solution – and all of the software involved is free (apart from Outlook and Exchange Server – for which the licenses are provided by my employer).

I’m using Google’s technology but I could also have used Microsoft products, as Sarah Perez describes with Windows Live Calendar and the Outlook Connector. Either should work – it’s just a matter of preference – and as I was already using Google Apps for one part of the solution, adding Windows Live Calendar into the mix seemed to over-complicate things slightly for me.

Finally, this information may be useful when diagnosing problems:

• Firstly, you may notice the warning triangle against my work calendar in the screenshot of Apple iCal. The issue is described in a Google Groups thread but closing and restarting iCal seemed to resolve it and it’s not come back since.
• Also, if Google Calendar Sync stops working – check out the Google Calendar Sync pages in the Google Help Center but also see Edmund Tse’s post describing how Outlook may disable Google Calendar Sync if it things there is a problem.
• Google also gives some pretty good advice for configuring Apple iCal to work with Google Calendar but there are some caveats, as described by ArsTechnica’s Infinite Loop.