Puerto Vallarta, Mexico - Next week, if you cross over the border from northern Mexico to southern Texas, you will arrive in the U.S. an hour before you left Mexico. That's because daylight saving time officially ends for most of Mexico at 2:00 am this Sunday.

Since Mexico did not go along with the changes that the United States made to established daylight savings time in 2007 to save energy, the shift from daylight savings time to standard time in most of Mexico will take place this Sunday, October 25th at 2 am, while U.S. citizens will not set their clocks back until 2 am on Sunday, November 1, 2015.

Ten northern border municipalities observe the same DST schedule as the United States. They are: Acuna, Anahuac, Juarez, Matamoros, Mexicali, Nuevo Laredo, Ojinaga, Piedras Negras, Reynosa, and Tijuana. But the rest of Mexico will be an hour behind the U.S. for the next week, something visitors may find useful to know - especially those arriving by cruise ship or airplane.

If you are here in Puerto Vallarta, be sure to set your clocks back one hour before going to bed on Saturday night. This is also a good time to check the batteries in your smoke detectors, an equally important task.

See The World Clock for a list of current times around the world, and which places are observing DST at the moment. (Marked by * on The World Clock.)