#!/usr/bin/perl

use warnings;
use strict;
use Date::Manip qw(); # I strongly recommend version 5.54

our $TZ = 'GMT'; # to avoid error message

while (<DATA>) {
    s/(-!-)/ $1/;   #to deal with strange comment format
    my @line = split /(\s+)/;
    1 while (Date::Manip::ParseDate(\@line));
    $_ = (join "", @line) || "\n";
    print;
}

__DATA__
09:12: 5:14:29-!- {more garbage goes here} 
09:12: 5:14:37 
09:12: 5:14:37
2008-12-12 00:39 * {more stuff here}
2008-12-12 01:17 < {data here}
2008-12-12 01:30
2008-12-12 01:31