I have built a script to create UM holidays schedules for Exchange Unified Messaging. Its a pretty manual process gathering all the holidays for a particular year and entering those details in to the script. If your deployment happens to be in New Zealand then I have already done the hard work for you for 2014 🙂
I have split the script in to 2 sections – The first section creates the holidays and the second applies the holidays to the specified Auto Attendant.
I have split national holidays and regional holidays so you will need to specify which regional holiday you want to apply in addition to the national holidays: