#!/usr/bin/env perl
=pod
datefilter

turn anything that looks like a Unix timestamp into a nicely formatted timestamp
will work for dates between
        % date -d @1500000000
        Thu Jul 13 21:40:00 CDT 2017
and
        % date -d @1999999999
        Tue May 17 22:33:19 CDT 2033

=cut

sub formatdate {
    $timestamp = shift;
    chomp($ret = `date +%F.%T -d \@${timestamp}`);
    return $ret;
}
BEGIN { $/ = $\ }
LINE: while (<>) {
    s/(1[5-9]\d{8})(\D|$)/formatdate($1)/ge;
    print;
}