How to convert text date to timestamp?

I'd look into DateTime and the parsing modules.

perl -MDateTime::Format::Strptime -le'$strp = DateTime::Format::Strptime->new( pattern => "%d.%m.%Y  %T", time_zone => "local"); $dt = $strp->parse_datetime("23.10.2011  11:35:00"); print $dt->epoch'
1319384100 at -e line 1.

Same as above, but not a one-liner:

use DateTime::Format::Strptime;
my $strp = DateTime::Format::Strptime->new(
   pattern => '%d.%m.%Y  %T',
   time_zone => 'local',
);
my $dt = $strp->parse_datetime('23.10.2011  11:35:00');
print $dt->epoch;

Using Time::Local , you can do:

use Time::Local;

my $date = '23.10.2011  11:35:00';
my ($mday,$mon,$year,$hour,$min,$sec) = split(/[\s.:]+/, $date);
my $time = timelocal($sec,$min,$hour,$mday,$mon-1,$year);
print $time,"\n",scalar localtime $time;

Output:

1319362500
Sun Oct 23 11:35:00 2011