that's exactly it Fred. the general rule is "Spring Forward, and Fall Back." that means when Autumn comes around, we turn our clocks back one hour, so for example 9:00 PM becomes 8:00 PM. then this lasts half a year until Spring comes along, and we turn the clock forward one hour.
New York is three hours faster than Cali, so if NY is at 5:30 PM, Cali is 2:30 PM. the Continental U.S. is seperated by four time zones, going from East to West... Eastern, Central, Mountain, and Pacific.