Good Friday (the 2nd) is a bank holiday but not a public holiday in the Republic of Ireland: All banks and many public services (eg post-office) are closed, but most public-transport will operate according to their normal Friday timetables.
Easter Saturday and Easter Sunday are not public holidays: usual Sat / Sun timetables generally apply.
Easter Monday is a public holiday and a bank holiday, and in most cases Sunday timetables apply.
Information from bus and train companies is summarised below. Always confirm details with the company. Bookings are recommended, because there are a number of events happening this weekend.
Covid-19 and public transport
All public transport services are running at 25% capacity, and are only available for essential travel. Pre-booking is strongly recommended.