There are revised times on all rail routes this Easter bank holiday weekend.
It is due to major works from today to Easter Monday from Connolly in Dublin to Howth and Belfast.
Iarnród Éireann spokesperson Barry Kenny said routes north of Connolly station will be particularly affected.
"So, from today through the Easter weekend, we are urging customers to check your time before travel for any changes," he said.
"Particularly if you are travelling on the route north of Connolly station, we have major works happening along the Dublin to Belfast line that will affect the northside DART, northern commuter and enterprise services.
"Those services will be suspended from Saturday onwards while we undertake a range of works."
Main image: Passengers and Iarnród Éireann Irish Rail train at Connolly station Dublin Ireland. Image: Jon Sparks / Alamy Stock Photo