My other question concerns the timezone America/Santa_Isabel. It seems that several sources imply that all of Baca California Norte is on the same timezone http://www.frontera.info/EdicionEnlinea/Notas/Noticias/13032010/435414.aspx http://www.notisistema.com/noticias/?p=251578 http://www.timeanddate.com/news/time/north-mexico-dst-change.html This is far from authoritative, but at least and indication that BCN might be one single timezone. I wonder if there has been any confirmation of the Santa Isabel timezone in BCN? I am not saying it is not there, I just haven't found any confirmation of it.
The "frontera.info" page above references http://www.conuee.gob.mx/wb/CONAE/comunicado_dgafid_012010 which has the virtue of being a governmental ("gobierno") source. The "gob.mx" page indicates that US rules get followed "en los municipios fronterizos de Tijuana y Mexicali en Baja California" rather than in the entirety of Baja California. Of course the law is one thing and what's actually happening may be quite another. --ado