In 2016, Chile introduced a new time zone for it south-most province Magallanes, and for this reason a new zone Zone America/Punta_Arenas -4:43:40 - LMT 1890 -4:42:46 - SMT 1910 Jan 10 -5:00 - -05 1916 Jul 1 -4:42:46 - SMT 1918 Sep 10 -4:00 - -04 1919 Jul 1 -4:42:46 - SMT 1927 Sep 1 -5:00 Chile -05/-04 1932 Sep 1 -4:00 - -04 1942 Jun 1 -5:00 - -05 1942 Aug 1 -4:00 - -04 1947 Apr 1 -5:00 - -05 1947 May 21 23:00 -4:00 Chile -04/-03 2016 Dec 4 -3:00 - -03 has been created. before it followed Zone America/Santiago -4:42:46 - LMT 1890 -4:42:46 - SMT 1910 Jan 10 # Santiago Mean Time -5:00 - -05 1916 Jul 1 -4:42:46 - SMT 1918 Sep 10 -4:00 - -04 1919 Jul 1 -4:42:46 - SMT 1927 Sep 1 -5:00 Chile -05/-04 1932 Sep 1 -4:00 - -04 1942 Jun 1 -5:00 - -05 1942 Aug 1 -4:00 - -04 1946 Jul 15 -4:00 1:00 -03 1946 Sep 1 # central Chile -4:00 - -04 1947 Apr 1 -5:00 - -05 1947 May 21 23:00 -4:00 Chile -04/-03 The new zone differs from zone Santiago at two points: - it does not have the 1946/47 DST - it differs from 2016 Dec 4, the reason of its creation. I wonder on which basis the 1946/47 DST was left out for Puntas_Arenas? Is that documented somewhere? The main reason why I ask: My two sources Shanks and Gabriel have always claimed that zone America/Santiago is only good for the province of Santiago, but that the rest of Chile did not have DST between 1927 and 1932. This is why in my private pre-1970 TZ extension I have an extra zone for 'rest of Chile besides Santiago' Zone America/Chile/Antofagasta -4:41:36 - LMT 1890 -4:42:46 - SMT 1910 Jan 10 # Santiago Mean Time -5:00 - -05 1916 Jul 1 -4:42:46 - SMT 1918 Sep 10 -4:00 - -04 1919 Jul 1 -4:42:46 - SMT 1927 Sep 1 -5:00 - -05 1932 Sep 1 0 follow America/Santiago which leaves out the 1927-1932 DST. It has however the 1946/47 DST. I have another zone, based on Shanks and Gabriel, for Vaparaiso, which leaves out the 1946/47 DST, but has a one-summer 1931/1932 DST. Zone America/Chile/Vina_del_Mar -4:46:16 - LMT 1890 -4:42:46 - SMT 1910 Jan 10 # Santiago Mean Time -5:00 - -05 1916 Jul 1 -4:42:46 - SMT 1918 Sep 10 -4:00 - -04 1919 Jul 1 -4:42:46 - SMT 1927 Sep 1 -5:00 - -05 1931 Sep 1 -5:00 Chile -05/-04 1932 Sep 1 -4:00 - -04 1942 Jun 1 -5:00 - -05 1942 Aug 1 -4:00 - -04 1947 Apr 1 0 follow America/Santiago Sadly, I have currently no sources for that beyond Shanks and Gabriel. We would need local newspaper archives from a non-Santiago newspaper for 1927-1932 to confirm. But it this is true, we have to assume that province Magellanes behaved like 'the rest of Chile' and not like Santiago before the split in 2016. That means that it should be: Zone America/Punta_Arenas -4:43:40 - LMT 1890 -4:42:46 - SMT 1910 Jan 10 -5:00 - -05 1916 Jul 1 -4:42:46 - SMT 1918 Sep 10 -4:00 - -04 1919 Jul 1 -4:42:46 - SMT 1927 Sep 1 -5:00 - -05 1932 Sep 1 -4:00 - -04 1942 Jun 1 -5:00 - -05 1942 Aug 1 -4:00 - -04 1947 Apr 1 -5:00 - -05 1947 May 21 23:00 -4:00 Chile -04/-03 2016 Dec 4 -3:00 - -03