Holidays calendar in an easy to import to Outlook calendar format

1.Create a new file "2015_Holidays.hol"

2. Add the required holidays text in the file in the following format:

[My 2015 Holidays] 4
New Year's day,2015/01/01
Coptic Christmas,2015/01/07
Easter,2015/04/12
Holiday #4,2015/10/20

3. Open the file where Outlook is installed to import the holidays directly to your profile calendar.

* Good reference about that same topic:
Add or delete holidays and custom events in your calendar:
http://office.microsoft.com/en-001/outlook-help/add-or-delete-holidays-and-custom-events-in-your-calendar-HP001230406.aspx