Updating outlook calendar with holidays
This definition file is available in various languages and contains holidays for 88 countries up to the year 2028.
This list is identical to the Outlook 2010 holidays (and to the Outlook-Tips file) and contains dates though 2020/2028.
Calendar Options and click the Add Holidays button. It can take a few minutes to add all the holidays, depending on how many countries you are adding.
While major religious holidays are listed with the holidays for some countries, there are separate listings for Christian, Islamic, and Jewish religious holidays.
Unfortunatly, it does a version check and only works with Outlook 2007 SP2 or SP3.
You can download the Microsoft installation file here.