Obligatory “DateTime rocks” post:

Anyone know how to calculate the epoch from the following data? Year Week_of_Year Day_of_Week

use DateTime;

my $epoch = DateTime
    ->new( year => 2002 )
    ->add( weeks => 10, days => 4 )
    ->epoch;
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date of the data point being the monday for the week.

use DateTime;

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

# ...

my $epoch = $dt->truncate( to => 'week' )->epoch;
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Makeshifts last the longest.

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
...
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use Date::Tie;

tie my %dt, 'Date::Tie', 
    weekday => 3,
    week => 5,
    weekyear => 2005,
    hour => 0,
    minute => 0,
    second => 0;

print $dt{$_}, " " 
  for qw( weekyear week weekday year month day hour epoch );
print "\n";

# 2005 05 3 2005 02 02 18 1107302400
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update: zeroed h:m:s