As many of you know, I live happily in the Apple Ecosystem but do virtually everything that doesn’t involve the browser in Emacs. One exception is my calendar. Events like “Renew ACM membership” or “Research ways of doing \(X\)” are added to my todo.org file and appear in my Org Agenda. Events with a specific, hard date and time attached, such as a doctors appointment, are added to my Apple calendar.
That’s a bit schizophrenic, of course, but it works well for me. The advantage of using the Calendar app is that the event and details about it are synched to my other Apple devices—including my iPhone—and so go with me everywhere. It’s possible, certainly, to use an app like beorg or organice to get my Org-mode events synched to my iPhone but as I said, this system works well for me.
A potential problem with maintaining one’s calendar in Org-mode is alerts. The Calendar app will alert you to upcoming events even when you’re not in Emacs. It wouldn’t do to miss an alert from Emacs because you happen to be, say, in the browser. Christian Tietze has in interesting post in which he explores the beginning of a solution to the problem of having Emacs generate MacOS native alerts. It turns out to be pretty easy although there are some edge cases. Those seem reasonably easy to fix so if you’re interested in that type of functionality, be sure to take a look at Tietze’s post.
There are other possibilities. One is to use Growl. It’s a notification system that can receive messages from other applications and show them on a system wide basis. There is, of course, an Emacs interface. Or two. Another possibility is John Wiegley’s alert module, which he describes as a Growl workalike. Doubtlessly these systems would require a bit of integration but since I’m satisfied with my hybrid solution, I haven’t looked into what would be involved.