For a simple solution that does not hit the server with any real time load you could run a script like:

my $dir = 'C:/test/';
opendir DIR, $dir or die $!;
while (my $file = readdir DIR ) {
    next unless $file =~ m/\.html?/;
    my @stat = stat $dir.$file;
    $mod_time = scalar localtime $stat[9];
    # do an inplace edit becaue it is less typing...
    `perl -pi.bak -e "s!(<MODTIME>[^<]*</MODTIME>)?</BODY>!<MODTIME>$m
+od_time</MODTIME></BODY>!i" $dir$file`;
}
closedir DIR;
[download]

This will read the contents or a dir. Find the .htm .html files. Do a stat on them to get the last modified time. Convert the stat value from epoch time to English. Insert the date in a token that we can modify in the future when we run the script again...

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print