Hi Mireillea,
Assuming you are using Project not connected to a Project Server - as far as
I know, no. If you are using Project Server, you may try posting the
question to the server newsgroup.
Using Project without server connection you could create a custom calendar
(Tools > Change Working time, new...) enter in the holidays manually and
then using Tools > Organizer, copy the custom calendar back into the
Global.mpt file. That calendar would then be available to all new projects.
I hope this helps. Let us know how you get along.
Julie