Daylight Saving Time is not observed in Hawaii, and by most of Arizona.
In summer, local time in Arizona is the same as Pacific Daylight Time (PDT).
The history of standard time in the United States began November 18, 1883, when United States and Canadian railroads instituted standard time in time zones.
Use of standard time gradually increased because of its obvious practical advantages for communication and travel.
Standard time in time zones was not established in U. law until the Standard Time Act of 1918 of March 19, 1918, also known as the Calder Act (15 USC 260).
When Daylight Saving Time begins turn your clocks ahead one hour.
At the end of Daylight Saving Time turn your clocks back one hour.
This will help facilitate trade and commerce between the two countries.