I just checked and this year will have a "horario de verano" from april first to october 27 (both sundays) in central Mexico and the change will be made at two am in the next day. I don't know if this will remain unchanged in the next years as it is stupid to change time in places with latitudes between the tropics as the length of the day does not change much. It seems that people in FIDE know little about Geography/Astronomy. Regards Guillermo M. Mallen mallen@kin.cyborg.com.mx