That depends on whether you're talking about America or Australia and (between some places) whether or not daylight saving time is in effect. In America, Eastern Standard Time is one hour ahead of Central Standard Time. In Australia, Eastern Standard Time is a half hour ahead of Central Standard Time. New York is one hour ahead of Regina, Saskatchewan in December, but it's two hours ahead in June. In December, Southampton Island is an hour ahead of Chicago, but they're on the same time in June. Adelaide is a half hour ahead of Queensland in December and a half hour behind it in June. Melbourne is a half hour ahead of Darwin in June but one and a half hours ahead in December.