From: Jesper Norgaard Welen Subject: Chile DST history
I took the time to check out in detail what the differences are from this source compared to tz database, based on the page http://www.horaoficial.cl/horaof.htm which contains timezone and time history in Chile since 1884. Here are the results if you apply those to the tz database (I might have made mistakes, since there are plenty of differences):
....
Note (1) Since the starting and ending of DST in 1927-1932 is a bit confusing (not covered by a decree of when it ended), I used the tz database as it was, since the first two transitions concur with the web page. It seems that the Chile web page claims that it stopped in 1928, but it doesn't mention a decree about that.
A table resolving these issues is at: http://www.horaoficial.cl/cambio.htm