Daylight Savings Time 2019: When Clocks Spring Forward

(the Patch) Daylight Saving Time begins Sunday, March 10, delivering the annual "spring forward" routine an extra hour of daylight in most places in America — most, because two U.S. states, Arizona and Hawaii, and a handful of territories don't observe the twice-annual ritual of the changing of the clocks.

Officially, the time change takes place at 2 a.m. on Sunday, but most cellphones and digital devices automatically update to the adjusted time.

Although the beginning of Daylight Saving Time is often associated with the beginning of spring, the Spring Equinox isn't until Wednesday, March 20.

Lawmakers in Hawaii and Arizona have declined to go along with the rest of the country on Daylight Saving Time. In Arizona, where the temperature can routinely reach a scorching 115 degrees, it's a matter of retaining earlier sunsets and cooler evening temperatures. But the decision not to participate in the time adjustment isn't absolute. Daylight Saving Time is observed on the Navajo Reservation in Arizona, which surrounds the Hopi Reservation, which doesn't.

Because Hawaii is far south of mainland states with a latitude similar to Mexico City, lawmaker there haven't seen the need to increase the hours of daylight. The U.S. territories of American Samoa, Guam, Northern Mariana Islands, Puerto Rico and the United States Virgin Islands also don't observe Daylight Saving Time.

Click here for 5 things to know about the time switch.