Calendar status now available on the web site

One of the major causes of confusion for our users, and consequently support e-mails sent to us is that we don't sync all your Google calendars. More accurately, we sync calendars that you have permission to write to, and that have timezone information.
The rationale for not syncing calendars that you can't update was that this could lead to devices becoming out of sync with Google. You could change an event from one of these calendars on your phone, but we would not be able to update the event in Google's system. We recently added code to support one-way sync for read-only calendars but found in trials that users didn't always want those events on their devices. So the feature is on hold until we have the capability for users to select which calendars are synced.
We don't sync calendars that lack timezone data for the simple reason that we need this information in order to create the responses we need to send to your phone. Without the timezone we'd either need to guess it, or not sync the calendar. The choice made was to skip those calendars. You can't create a calendar without timezone data using Google's web site, but we have seen cases where third-party applications and sync tools have done so.
A new feature on our site today gives users the ability to see which calendars will sync and the reason for any non-syncing calendars. Simply visit this page to see your list.