One of the terms you may hear or see while planning a visit to Ireland is “bank holiday”. Most of the bank holidays can be translated to “three day weekends” in US English…. These are the days defined by law in the Republic of Ireland when the banks are closed and most people have a day off. Most of the Bank Holidays are on a Monday, but not all. There are nine official bank holidays with a tenth unofficial day. Here is the complete list: 1-Jan - New Years Days 17-March - St.