This follows the release of Gmail Offline at the end of January. The offline Calendar news is a bit less exciting for a couple of reasons. For one thing, email is a lot more crucial for me than my calendar. For another, when announcing Gmail Offline, Google promised that offline Calendar support was coming sometime in “the next couple of weeks,” so there’s less surprise now. Still, this is a nice addition; it means that if I’m struggling to remember an appointment’s time or location (which I’ll admit happens far more often than it should), I can look it up, even if I can’t get a good wireless signal. Unless, of course, I forgot to put it in my Calendar — then it’s back to Gmail.
Calendar’s offline features appear to be more limited that Gmail’s. Most significantly, it’s “read only,” so you can’t add new events (in Gmail, you can write emails that get sent once you’re online again). There’s also no “flaky connection” mode, which is a hybrid between full online access and offline mode.
It’s also worth noting that this support is rolling out to Apps customers first, not to users of the consumer product. That’s unusual for Google, as Google Operating System points out, but it makes sense in this case, since business customers probably get a lot more use out of their calendars. Unfortunately, that’s a bit of drag for me, since I consolidate all my calendar information in my personal account — and even if I share my consumer calendar with my Apps account, it won’t be synchronized. Until Google rolls out support for consumer users, I’ll have a synced Apps calendar, but it will be completely empty.