My Calendar app in OS X is pretty slammed with all different kinds of calendars to keep me organized. I have one for work, personal items, birthdays, holidays and even calendars to keep both my MacBook Pro, iPhone and iPad batteries properly calibrated are in there too. Some are calendars that I have created and some are subscribed calendars from Apple's website.
Recently it seems that Apple has done away with the Jewish holiday calendar for some reason or another. At first, I thought it might have been a bad link or the calendar's file was moved on the Apple servers.
However, after some digging around on the calendar subscription page, it seems that Apple is no longer offering the Jewish holiday calendar for some reason.
I wasn't too worried, however, since I knew there must be another resource I could use. During my search for a Jewish holiday calendar replacement, I stumbled across a brilliant resource: Hebcal.com.
Hebcal was originally written for *nix platforms by Danny Sadinoff in 1994 and was updated by Michael Radwin in 1999 to include a web interface to allow export of calendar information into different formats. This awesome resource actually provides more granularity with calendar information that a standard Hebrew calendar might not show. Not only will it display the major holy days (Rosh Hoshanah, Yom Kippur, etc.), but you can elect to customize the calendar with minor holidays, modern holidays, special Shabbatot, Rosh Chodesh. Options are also available to display candle lighting times and the Hebrew year, among others.
The awesome part comes in when you go to export the calendar. You can choose to publish the calendar to a variety of desktop applications such as Outlook 97-2010, Outlook 2011 for Mac, Apple iCal, iPhone and iPad, Google, Windows Live, Yahoo! and Palm Desktop. Outlook.com users will also be pleasantly surprised: since Microsoft has elected to leave Windows Live Calendar integrated with Outlook.com email accounts, it will also display seamlessly for you. There's even an OS X Dashboard widget from Mark Saper that uses the information from Hebcal.com's API to supply information weekly Torah readings, candle lighting times and more, based on your zip code. The widget was originally published on October 10, 2005, but I have tested it in Mountain Lion and it appears to work flawlessly.
If you're looking for a substitute for the standard Jewish holiday calendar for your Mac or other calendar application, I suggest giving Hebcal.com a try and if you have a Mac, don't forget to check out the Dashboard widget.