It changes on Sunday, April 4th, 2009.
Puerto Vallarta is 5 hours ahead of Hawaii from the 1st Sunday of April to the last Sunday of October (during Daylight Saving Time in Mexico) and 4 hours ahead the rest of the year.
Most of México, including Puerto Vallarta, observes Daylight Saving Time from the 1st Sunday of April until the last Sunday of October. In 2013, those dates are April 7 - October 27.
No. Both zones could end up with two hours of difference, due to the fact that daylight saving time starts on different dates fort each region.
No. Puerto Rico observes Atlantic Standard Time all year.
No. Daylight savings time was first observed in Mexico since April 7, 1996.
Mexico's three time zones are the same as Canada's westernmost three time zones. However, Canada and most of Mexico have different Daylight Saving Time schedules, and Saskatchewan, Canada and Sonora, Mexico don't do Daylight Saving Time.
Some parts of Mexico observe daylight savings time; some don't. I suggest the Date and Time web site for specifics. In general terms however, Mexico's daylight saving time starts on the first Sunday of April and ends on the last Sunday of October.
Like most of the Mountain time zone, New Mexico observed Daylight Saving Time from 1918 to 1921, year-'round during World War II, and from 1965 to the present.
Arizona, Hawaii, and Puerto Rico do not follow daylight saving time.
Some locations that do not follow Daylight Saving Time include Hawaii, most of Arizona, Puerto Rico, Guam, American Samoa, and the US Virgin Islands. Additionally, countries near the equator typically do not observe Daylight Saving Time.
In 2011, Mexico begins Daylight Saving Time on April 3 - set your clock(s) forwardone hour at 2:00 AM. It ends on October 30 - set your clock(s) back one hour at 2:00 AM.
The states that do not observe Daylight Saving Time are Arizona (with the exception of the Navajo Nation) and Hawaii. Additionally, the territories of Guam, Puerto Rico, the US Virgin Islands, and American Samoa also do not participate in Daylight Saving Time.