9:00 pm EST might be unsuitable for EDT time zone
When planning a call between Eastern Standard Time and Eastern Daylight Time, you need to consider time difference between these time zones. EST is 1 hour behind of EDT.
It is 9:00 pm in EST. This does not fall within the span of usual working time between 10:00 am and 6:00 pm in EDT, but it still might be suitable to arrange a meeting, since it would be 10:00 pm in EDT, which is between 7:00 am and 11:00 pm EDT time.