Dear Alois and team, thank you so much for the quick followup. I tried doing a quick search for newspapers of the era, but it is proving to be difficult.
This website gave me hope for a moment, but so far no luck finding a newspaper that would talk about the time change (would need to be one from the last Sunday of April or October, to be relevant). https://latinonewspapers.uh.edu/s/eng/publicationlist?page=7&sort=dcterms:spatial%20asc Of course Mexicali, being the capital city of the Baja California state, has a vast newspaper archive, but unfortunately they don’t have an online presence and an in-person visit is out of the question as I’ve lived in Germany for years now. So sadly, all I can contribute right now is circumstantial evidence: I know that from the time I was born until I left Mexicali (ca. 2000) we always used DST because to have a different time than our neighboring city of Calexico would have been laughable. Calexico was an integral part of our culture and society; for example, everyone would cross the border to go shopping on the weekends or, if the gas was cheaper in the US side that week, everyone would just cross the border to quickly fill the tank and come back (these were simpler, pre-9/11 times). A different time zone would have been quite disruptive and I know for a fact that this was never the case while I lived there (1973-2000). But of course, I have no way to prove this except my word. The hospital I was born in was in fact located two blocks away from the border, and if I set my birth data to show Calexico instead of Mexicali, I do get the correct chart and time. Anyway, if I ever come back to my hometown I will try to find an old newspaper, until then, thank you so much for your help and the attention to this matter. All the best, - Beto Ruiz Alonso betoruizalonso.com <http://www.betoruizalonso.com/>instagram.com/betoruizalonso <http://www.instagram.com/betoruizalonso> > On 29. Jul 2025, at 15:26, Alois Treindl <[email protected]> wrote: > > I have a few more data from the official bulletin for DST begin or end in > Baja California > 1964 > 1967 > 1969 > 1972 > > 1973 (already sent) > > 1974 > 1975 > 1976 > > I do not know whether it is safe to assume that it also applied in the years > where I did not > yet find proof. > > The 1974 end of DST contains a reference to an Acuerdo of 1973-dec-20 which I > could not find. > It was the winter of the 'oil crisis' if I remember correctly. The US started > DST already on 6-jan-1974. > > One might assume that Baja California, which followed US-CA in all these > other yours, did the same. > > > > > > On 29.07.2025 13:59, Alois Treindl via tz wrote: >> TZ maintains for zone America/Tijuana that there was not DST observed >> between 1961 and 1975. >> >> >>> # Baja California >>> Zone America/Tijuana -7:48:04 - LMT 1922 Jan 1 7:00u >>> -7:00 - MST 1924 >>> -8:00 - PST 1927 Jun 10 >>> -7:00 - MST 1930 Nov 15 >>> -8:00 - PST 1931 Apr 1 >>> -8:00 1:00 PDT 1931 Sep 30 >>> -8:00 - PST 1942 Apr 24 >>> -8:00 1:00 PWT 1945 Aug 14 23:00u >>> -8:00 1:00 PPT 1945 Nov 15 # Peace >>> -8:00 - PST 1948 Apr 5 >>> -8:00 1:00 PDT 1949 Jan 14 >>> -8:00 - PST 1950 May 1 >>> -8:00 1:00 PDT 1950 Sep 24 >>> -8:00 - PST 1951 Apr 29 2:00 >>> -8:00 1:00 PDT 1951 Sep 30 2:00 >>> -8:00 - PST 1952 Apr 27 2:00 >>> -8:00 1:00 PDT 1952 Sep 28 2:00 >>> -8:00 - PST 1954 >>> -8:00 CA P%sT 1961 >>> -8:00 - PST 1976 >>> -8:00 US P%sT 1996 >>> -8:00 Mexico P%sT 2001 >>> -8:00 US P%sT 2002 Feb 20 >>> -8:00 Mexico P%sT 2010 >>> -8:00 US P%sT >> A user of our astrology service, born in 1973 in he border town Mexicali >> claimed that >> they observed DST in his town, just like on the other side of the border in >> California, when he was >> born on 30 May 1973. >> >> I did a quick newspaper archive research on https://hndm.iib.unam.mx/ >> and found that >> >> Título: >> Periódico Oficial del Estado de Baja California Norte >> Fecha: >> 1973-04-20 >> <>states clearly that DST was observed from last Sunday in April to last >> Sunday in October. >> >> This means the the TZ table above is false, at least for 1973. >> I assume that the same is the case for several other years. >> >> I attach the screenshot for 1973 >> >> The page >> https://hndm.iib.unam.mx/consulta/publicacion/visualizar/558075be7d1e63c9fea1a3b2?pagina=558a34887d1ed64f16a710da&coleccion= >> should allow to search for other years as well. >> >> I used the keywords hora legal for my search, though do not see that now in >> the URL. >> >> >> >> <> >> > <1964_begin_dst_baja_california.png><1967_begin_dst_baja_california.png><1969_end_dst_baja_california.png><1970_end_dst_baja_california.png><1976_begin_dst_baja_california.png><1975_end_dst_baja_california.png><1974_end_dst_baja_california.png><1972_begin_dst_baja_california.png><1973_begin_dst_baja_california.png>
