Names change during the daylight savings period to Include the word "Daylight." Such as Eastern Daylight Time.
This is a period of several months Daylight saving (not savings) time that is set up supposedly to save energy.
The idea is to be able to be more active and take advantage of the longer and later daylight hours.
The official US Daylight Saving Time Schedule started this year of 2010 on March 14 and will officially end on Nov.7.
To help you to remember to move your clocks forward an hour in the Spring and turn around and move them back an hour in the Fall is a coined phrase "Spring forward and Fall back."
All time zones change but Arizona does not, due to better Air Conditioning hours staying and cooler work times in the hot summer starting early etc on the regular time.
Therefore, Arizona is an hour different then adjacent states part of the year and the time difference during daylight savings time changes.
California and Arizona, who are in two different time zones, have the same time during daylight savings time for example Hawaii does not change, and Alaska recently passed a bill to stop following it as well.