GMT to EDT conversion in Teradata - response (3) by Georg75

If you have to take into account dailight savings time you should use the following syntax:
Found in TD 14.0 docu (SQL Functions, Operators, Expressions, and Predicates; Chapter 7: DateTime and Interval Functions and Expressions; "Strings that follow different DST and standard time zone displacements").
Tested on TD 13.10

select
 cast('2013-04-21 10:00:00' as timestamp(0)) as utc_summer
,utc_summer at time zone 'America Eastern' as edt_summer_time
,cast('2013-12-21 10:00:00' as timestamp(0)) as utc_winter
,utc_winter at time zone 'America Eastern' as edt_winter_time
;

Result:
utc_summer      21.04.2013 10:00:00
edt_summer_time 21.04.2013 06:00:00
utc_winter      21.12.2013 10:00:00
edt_winter_time 21.12.2013 05:00:00