Luas drivers have rescheduled their strikes in June so as not to inconvenience Leaving and Junior Cert students.
Drivers have announced six further strike days next month - a move Luas operator Transdev said was designed to cause maximum disruption to customers.
Trade union SIPTU says it was never their intention to clash with the State exams.
Owen Reidy, Divisional Organiser with SIPTU, said: "The last thing anybody wants to do is put teenagers or any young people under any more pressure than they are on with such exams.
"So, they have decided that Wednesday 8th, Thursday 9th and Friday 10th of June, the four-hour stoppages will change and will commence at 6pm and end at 10pm.
"That should avoid any discommoding of any Leaving Cert or Junior Cert pupils."