.HOL File Extension

Calendar file used by Microsoft Outlook, an email and calendar application; saves the dates of holiday events that are displayed on the Outlook calendar view when the application is open; can be customized manually with a text editor to share company-specific calendar events.

The Outlook installation includes a predefined HOL file called outlook.hol in the following directory:

C:\Program Files\Microsoft Office\Office 12\[LCID]\

You can add new holidays to this file by opening it in a text editor and appending holidays to the end of the file in the following format:

[Description]
Holiday description, yyyy/mm/dd
Holiday description, yyyy/mm/dd
...

The next time you open Outlook, these new holidays will display on the calendar. You can share this updated file with team members so they have the same holiday events.