Question regarding date formats

We are currently running RT version 3.0.11-3, installed via the Debian
package.
Other software versions -
Perl: v5.8.4
DBIx::SearchBuilder: 1.26
Apache: 2.0.54

Currently, all times are being displayed in GMT. Can this be changed to
default the display to ET?
Also, when entering a date in the ‘Dates’ box, such as setting a Due date,
the date is changed to sometime next year if the format we enter the date in
is not ‘yyyy-mm-dd hh::mm’. If we use the format mentioned, the date is
parsed correctly. Is this a bug or do we need to change something on our
end?

Thanks,
Dave