In a rare feat, Florida signed time zone legislation this month that would recognize daylight saving time (more sunlight in the evenings, less in the mornings) throughout the year. Such a change would have an unusual effect: for half of the year, the state would be an hour ahead of the rest of the east coast and in its entirely own time zone from the rest of the country.
Bottom line: States are currently free to observe standard time throughout the year (Hawaii and Arizona do). But theres a catch; For the Florida law to go into effect, Congress would need allow states the autonomy to recognize daylight saving time year round. It does not appear likely to do so.