This will print the list of epochs for all mondays in the year:

use Date::Tie;
use strict;

tie my %dt, 'Date::Tie', 
    weekday => 1,
    week => 1,
    weekyear => 2005,
    hour => 0, 
    minute => 0, 
    second => 0;

while ( $dt{weekyear} == 2005 )
{
    print $dt{epoch}, "\n";
    $dt{week}++;
}

1104710400
1105315200
1105920000
1106524800
1107129600
1107734400
...
[download]