PS: on second thought, could it be that the lines for 1942 are generally in error: Rule Chile 1942 only - Jun 1 4:00u 0 - Rule Chile 1942 only - Aug 1 5:00u 1:00 S Rule Chile 1946 only - Jul 15 4:00u 1:00 S Rule Chile 1946 only - Sep 1 3:00u 0:00 - They make no sense, because according to this, - Jun 1942 line is superfluous - Aug 1942 sets DST in force until next cancellation of DST in Sep 1946, - JUL 1946 line would be superfluous, as well. Should it not rather be: Rule Chile 1942 only - Jun 1 4:00u 1:00 S Rule Chile 1942 only - Aug 1 5:00u 0 - Rule Chile 1946 only - Jul 15 4:00u 1:00 S Rule Chile 1946 only - Sep 1 3:00u 0:00 - But when I look at the reference, http://www.horaoficial.cl/historia_hora.html it does not contain anything about DST in 1942.