Okey!
I think I know what itâs the problem.
The change between summer and winter time.
Check this news,
El Gobierno chileno de Michelle Bachelet, por medio de su ministro de EnergĂa, MĂĄximo Pacheco, ha anunciado que Chile repondrĂĄ su horario de invierno por tres meses, entre el 14 de mayo y el 13 de agosto. La medida representa un cambio de opiniĂłn a lo que el propio Ejecutivo habĂa defendido hasta hace solo 45 dĂas.
The Chilean government of Michelle Bachelet, through its Minister of Energy, Maximo Pacheco, announced that Chile will replace its winter schedule for three months, between May 14 and August 13. The move represents a change of what the government itself had defended until just 45 days ago.
So, what it means is last May 14 they changed to winter time 
More Info 
http://www.timeanddate.com/worldclock/chile/santiago