EDT may refer to:
There are at least two major text editors named EDT: one was made by Digital Equipment Corporation, the other by RCA for its TSOS operating system for its Spectra series mainframes. The RCA version was later sold to Sperry Univac (which later became Unisys), was released for the VS/9 operating system, and is currently in use on Fujitsu BS2000 OSD Mainframes and the BS2000 Operating system. Other than sharing a name, neither editor had any relation to each other in method of operation, use, or functionality.
Digital's EDT ran on minicomputers, could respond to single keystrokes, and used function keys to implement commands to the editor. RCA/Univac/Fujitsu's EDT ran on mainframes, could only respond to a full line (or multiple lines separated by return) after the transmit key is pressed, and uses commands are entered in the typed-in text when preceded by the command symbol (the at sign "@" which can be changed.)
EDT is a text editor that was developed by Digital Equipment Corporation (DEC) for use on its PDP-11 series of computers (including RSX-11,RSTS/E and RT-11), and later for its VAX/VMS series as well. EDT was introduced originally as a line-mode editor. The screen mode was developed first as the Keyboard Editor (KED) on RT-11 as part of the FMS-11 project by Darrell Duffy; EDT on the other operating systems was then enhanced to be compatible with KED.
The Eastern Time Zone (ET) is a time zone encompassing 17 U.S. states in the eastern part of the contiguous United States, parts of eastern Canada, the state of Quintana Roo in Mexico, Panama in Central America and the Caribbean Islands.
Places that use Eastern Standard Time (EST) when observing standard time (autumn/winter) are 5 hours behind Coordinated Universal Time (UTC−05:00).
Eastern Daylight Time (EDT), when observing daylight saving time (spring/summer) is 4 hours behind Coordinated Universal Time (UTC−04:00).
In the northern parts of the time zone, during the second Sunday in March, at 2:00 a.m. EST, clocks are advanced to 3:00 a.m. EDT leaving a one-hour "gap". During the first Sunday in November, at 2:00 a.m. EDT, clocks are moved back to 1:00 a.m. EST, thus "duplicating" one hour. Southern parts of the zone (Panama and the Caribbean) do not observe daylight saving time.
The Uniform Time Act of 1966 ruled that daylight saving time would run from the last Sunday of April until the last Sunday in October in the United States. The act was amended to make the first Sunday in April the beginning of daylight saving time as of 1987. The Energy Policy Act of 2005 extended daylight saving time in the United States beginning in 2007. So local times change at 2:00 a.m. EST to 3:00 a.m. EDT on the second Sunday in March and return at 2:00 a.m. EDT to 1:00 a.m. EST on the first Sunday in November. In Canada, the time changes as it does in the United States.