18:00->03:00GMT = 13EST-22EST or 1PM - 10PM EST
03:00->09:00GMT = 22EST-4EST or 10PM - 4AM EST
09:00->18:00GMT = 4EST-13EST or 4AM - 1PM EST

Thanks to Burebista for cathcing our mistake.

Goonie, I do not know where you came up with these limits.
The limits for the interval do not have to be exactly these, nobody required that we should select one of these 3 intervals and there is no logic behind these boundries.

These times so not make any sense. I can't vote for any of them.