Eastern Daylight Saving Time was not in use on the 21st of December 2010 (unless you are referring to Australian Eastern Daylight Saving Time). Even if it were, you would need to specify a city or a set of geographical coordinates.
8:34 PM Eastern Daylight Saving Time
at 4:20 PM CST
On March 19, 2011, sunrise will be at 7:02 AM Eastern Daylight Time, and sunset will be at 7:06 PM EDT. Daylight Savings Time starts on March 13, 2011.
Sunrise at Cleveland on 21 December 2011 was at 7:49 AM Eastern Standard Time.
On October 16, 2010, in New York City, sunrise will be at 7:07 AM Eastern Daylight Time, and sunset will be at 6:15 PM EDT. Source: see Related Link below.
Today, March 5, 2011, in New York City, sunrise was at 6:25 AM Eastern Standard Time, and sunset was at 5:50 PM EST. Daylight Savings Time begins on March 13, 2011.
On April 18, 2011, sunset in Columbus, Georgia was at approximately 8:00 PM Eastern Time.
Sunrise: 5:24am Sunset: 8:28pm Full Moon: 3:15pm
4:00 P.M. Eastern Standard Time.
The sunset on December 12, 2009 was 4:20pm. The sunrise was at 7:09am.
On April 17, 2011, in New York City, sunrise will be at 6:15 AM Eastern Daylight Time, and sunset will be at 7:36 PM EDT. For more sunrise/sunset times for all the world's major cities, see the Related Link below.