A pub in Ireland can legally open at 10:30 in the morning except on Sunday, when service must wait until 12:30 in the afternoon.
Closing time on Monday through is 11:30. On Friday and Saturday, it's 12:30, and on Sunday, 11:00.
At closing time, a publican is required to stop serving alcoholic drinks. The clientelle are allowed a bit of "drinking-up time, " and then must leave the premises. The Vintners' Federation of Ireland (the official body governing public houses) maintains that "drinking-up time is 30 minutes."
There are exceptions, of course, when you'll get a drink after the legal closing time. But this is at the discretion of management, and not something to write about here.
(Padraig Cribben, Chief Executive of the aforementioned VFI, informs me that "A late drink is not at the discretion of management. To legally get a late drink there must be what is called a special exemption in place. That can only be granted by the courts.")
Another solution is to get take-away* from the "off licence" (beer/wine/liquor store) and go back to somebody's "gaff."*In 2009, claiming the need to prevent youth drinking (which was already illegal, ) Ireland legislated that off-licences would have to close at 10 o'clock. Some don't, or not completely but, again, that's not something to to be described here. __ ___ __
* Sometime between my departure, the Thursday closing-time of Irish pubs changed from 12:30 to the normal weekday time of 11:30. Before then, it was essentially one of the "weekend" nights.