N.Y.C. Admin. Code § 2-106: § 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.