And here's a really obvious (yeah right!) way of making Lynn's example work:

declare @DateVal datetime;

set dateformat mdy;

set @DateVal = '2013-02-14T00:00:00';

select @DateVal;

go

declare @DateVal datetime;

set dateformat dmy;

set @DateVal = '2013-02-14T00:00:00';

select @DateVal;

go