Issues arise whether to observe new DST rules for Acuña and Piedras Negras in state Coahuila, Mexico Coahuila no acatará horario de verano (in spanish) http://www.exonline.com.mx/diario/noticia/primera/pulsonacional/coahuila_no_... ara_horario_de_verano/889695 or http://www.worldtimezone.com/dst_news/dst_news_mexico052.html Alexander Krivenyshev, http://www.WorldTimeZone.com