Questions about Time Zones

UTC = Universal Coordinated Time. GMT = Greenwich Mean Time. For the purposes of meetings they can be considered interchangeable.
UTC is the reference from which ALL other time zones are calculated.
It corresponds to the notional line of 0 degrees longitude which passes through Greenwich in London, UK
Your time zone is given by GMT +/- a number of hours.
In New York, the time zone in the winter is EST (Eastern Standard Time), defined as GMT-5, so if GMT is 19:00, the time in New York is 14:00.
In New York, the time zone in the summer is EDT(Eastern Daylight savings Time), defined as GMT-4, so if GMT is 22:00, the time in New York is 18:00.
Current GMT time is:

Current Time UTC/GMT