Depends some on where you are, in my area it is new years eve, new years day, memorial day, independence day, labor day, thanksgiving and the day after, christmas day.
You should be able to find it on UPSers under Our Company. Then click on Benefits and Compensation then click on Paid Time Off then click on Employee Holidays.
Holidays listed on UPSers when I logged on were the same as those IWork came up with.