use DateTime;

my $epoch = DateTime
    ->new( year => 2002 )
    ->add( weeks => 10, days => 4 )
    ->epoch;

##</code><code>##

use DateTime;

my $dt = DateTime
    ->new( year => 2002 )
    ->add( weeks => 10, days => 4 );

# ...

my $epoch = $dt->truncate( to => 'week' )->epoch;