Good news for Google Calendar users: Support for offline viewing in now officially available, albeit with some notable limitations.Offline Google Calendar support has been available for Google Apps users since early February. Earlier this week, however, Google extended offline calendar support (not surprisingly, as a beta release) to anyone with a Google account.

To use it, you'll need to install the open-source Google Gears browser extension, which is available for a variety of desktop and smartphone operating systems.

According to the blog post announcing the release, the offline functionality is still limited in a number of ways; users can't, for example, add, edit, or search calendar events in offline mode. That makes it useful mostly for quick-and-dirty calendar checks; for more advanced offline support, Google recommends using .Mozilla Sunbird, which can sync with Google Calendar using the open CalDav standard.