 These time zones were adopted on 1 January 1912.Daylight saving time ("Hora de Verão", in Portuguese) was observed for the first time in 1916, during World War I, and it consisted in advancing clocks by 1 hour.In that year, DST was observed from 17 June to 1 November but in following years until 1921, it was observed from 1 June to 14 October.