If you are staying in Puerto Vallarta, the time will not change for you since it is in the Central Time Zone also. If you are staying in
Nuevo Vallarta, to the north of PV, you will be in the Mountain Time Zone (or one hour behind). The time zone changes when you drive across the Ameca River to the north of PV into the Mexican State of Nayarit. Puerto Vallarta is in the Mexican State of Jalisco.