"Where America's Day Begins" (4)
I believe the answer is:
guam
'where america's day begins' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for guam that I've seen before include "Largest of the Mariana Islands" , "US island east of the Philippines" , "NW Pacific island with large US base" , "US unincorporated territory in the western Pacific" , "Island in the West Pacific" .)