Ireland uses Irish Standard Time (IST, UTC+01:00; Irish: Am Caighdeánach Éireannach) in the summer months and Greenwich Mean Time (UTC+0) in the winter period. In Ireland, the Standard Time Act 1968 legally established that the time for general purposes in the State (to be known as standard time) shall be one hour in advance of Greenwich mean time throughout the year. This act was amended by the Standard Time (Amendment) Act 1971, which legally established Greenwich Mean Time as a winter time period. Ireland therefore operates one hour behind standard time during the winter period, and reverts to standard time in the summer months. This is defined in contrast to the other states in the European Union, which operate one hour ahead of standard time during the summer period, but produces the