DST, as also advanced them by another hour during some months of those years, coming to have clocks two hours ahead of GMT, effectively observing "double DST". Portugal returned to GMT following the end of the war in 1945, and one hour of DST continued to be observed. In 1948, it was approved that DST should be observed from the first Sunday in April to the first Sunday in October. From 1966, DST was observed year-round, so that, in practice, Portugal changed its time zone from WET (UTC+00:00) to CET (UTC+01:00). However, due to the later sunrises and sunsets, many complaints accumulated: on winter mornings, people went to work under a completely dark sky, and at 09:00, when school classes started, the sun was still rising, which eventually had repercussions on students' school performance and their safety during morning trips from home to school. Furthermore, in the 1970s, the idea of reintroducing DST as an energy saving measure gained strength in Europe as well as in Portugal. However, although there were so many complaints in the country with the use of UTC+01:00 year round, it became clear to policymakers that if DST was to be re-introduced, it could never be observed as CEST (UTC+02:00), and the only solution was to re-adopt WET as standard time. Therefore, Portugal re-adopted Western European Time (UTC+00:00) as its standard time in 1976. DST started to be observed every year as WEST (UTC+01:00), usually from early April to later September. From 1981 on, DST started to be observed from the last Sunday in March to the last Sunday in September. In 1986, time in Portugal began to be calculated in accordance with UTC rather than GMT. Switch to Central European Time In 1992, during the government of Aníbal Cavaco Silva, by Decree-Law 124/92, mainland Portugal officially changed its time zone from Western European Time to Central European Time. Unlike the 1966 change to CET, DST was observed as Central European Summer Time (UTC+02:00), from the last Sunday in March to the last Sunday in September. The measure, approved without the consultation of Lisbon Observatory, had the intention of promoting energy savings, in order that "Portugal follow, in work schedules, the countries with which it maintains more frequent contacts" (DL 124/92) and so promoting economic growth. However, the measure quickly proved to be a failure in achieving its objectives and became unpopular: on winter mornings, the