The unnamed cleric successfully complained to the EU Ombudsman, P Nikiforos Diamandouros, that the diary had contained other religious holidays such as the Jewish and Islamic New Years but had left out key Christian celebrations like Christmas and Easter.
The European Commission publishes the Europa diary every year for students in secondary schools in the EU as a tool for homework and other notes.
The 2010/2011 edition of the diary was distributed to more than 3.2 million students in over 21,000 secondary schools in the EU.
Last January, the Irish priest made an official complaint to the EU Ombudsman that the European Commission failed to include Christian holidays.
The priest called on the EU to apologise for the error, to recall copies which had already been distributed and to reprint the diary.
Mr Diamandouros notified the priest last February that the commission had formally apologised on an EU website for what it called “a regrettable error”.
The European Commission also sent a correction notice to all the schools last February to advice teachers that some important religious holidays had been omitted from the diary. It also promised that the main public holidays will be included in all future editions.
The EU Ombudsman said he was not convinced that the priest’s request to have the diary recalled and reprinted would be “proportionate” given it will only be used for a few more months.