$ perl -wE 'use Date::Manip; say UnixDate("epoch 1264108407", "%O\n")' 
2010-01-21T22:13:27

##</code><code>##

$ perl -wE 'use Date::Manip 6.0; my $d = Date::Manip::Date->new; $d->parse_format("%a %b %d %T %Y %z", "Thu Jan 21 17:13:27 2010 -0400"); say $d->printf("%O");'
2010-01-21T17:13:27