Big Apple
"Big Apple" is a nickname for New York City. It was first popularized in the 1920s by John J. Fitz Gerald, a sports writer for the "New York Morning Telegraph". Its popularity since the 1970s is due in part to a promotional campaign by the New York tourist authorities.
Time in New York
The state of New York uses the Eastern Time Zone (UTC-5) with DST (UTC-4). Because the largest city in the state, New York City, is the largest city in the United States, and because the Eastern Time Zone is used in the nation's capital, Washington, D.C., in addition to the fact that a majority of the nation's population is in that time zone, Eastern Time is the most commonly used time zone for television scheduling. Therefore, if a program airs at 7:00 PM Eastern Time, the network will usually advertise it by saying "Tonight at 7, 6 Central", or just "Tonight at 7".