As a NYC resident, I can assure you we follow US time :)
Just for completeness, here's the link to the actual law on the NY state website:
§ 2-106 Daylight saving time; effect thereof on public proceedings.
The standard time throughout the city of New York is that of the
seventy-fifth meridian of longitude west from Greenwich, except that at
two o'clock ante-meridian of the last Sunday in April of each year such
standard time throughout the city shall be advanced one hour, and at two
o'clock ante-meridian of the last Sunday in October of each year, such
standard time shall, by the retarding of one hour, be returned to the
mean astronomical time of the seventy-fifth meridian of longitude west
from Greenwich, and all courts, public offices and legal and official
proceedings shall be regulated thereby.
-Andrew