Ireland therefore operates one hour behind standard time during the winter period , and reverts to standard time in the summer months .
This act was amended by the Standard Time ( Amendment ) Act 1971 , which legally established Greenwich Mean Time as a winter time period .
Ireland operates one hour behind standard time during the winter period , and reverts to standard time in the summer months .
This act was amended by the Standard Time ( Amendment ) Act 1971 , which legally established Greenwich Mean Time as a winter time period .