The National Archives of Ireland (and its free Genealogy Service) will be closed on Monday 5 June, reopening at 9:15am on Tuesday 6 June.

Exhibitions at the National Library of Ireland will be open on Saturday and Sunday as usual (Kildare Street: Saturday 9.30am–4.45pm; Sunday: 1:00pm–4:45pm. National Photographic Archive Gallery in Temple Bar: Saturday 10am–5pm; Sunday: 12pm–5pm). Bank holiday Monday opening will be from 12pm to 5pm only at both locations.
Dublin City Library & Archive will be closed on Saturday 3 June and Monday 5 June, as will all branch libraries in the Republic.
The General Register Office Research Room at Werburgh Street, Dublin, will not open on Monday 5 June. It will reopen at 9:30am on Tuesday 6 June.
The Research Room of the Representative Church Body Library will be closed on Monday 5 June, reopening at 9:30am on Tuesday 6 June.
NOTE: This bank holiday applies only in the Republic; Northern Ireland institutions (as all in the UK) will be working to normal hours, having had their early summer holiday the previous week.