#!perl
eval 'exec /usr/bin/perl -S $0 ${1+"$@"}'
    if $running_under_some_shell;
                        # this emulates #! processing on NIH machines.
                        # (remove #! line above if indigestible)

eval '$'.$1.'$2;' while $ARGV[0] =~ /^([A-Za-z_0-9]+=)(.*)/ && shift;
                        # process any FOO=bar switches

while (<>) {
    @Fld = split(' ', $_, -1);
    $tm = $Fld[(1)-1] . ' ' . $Fld[(2)-1] . ' ' . $Fld[(3)-1];
    ;

    print $_ if $start lt $tm && $tm lt $end;   #???    #???
}
Please check my work on the 2 lines I've marked with "#???".
The operation I've selected may be wrong for the operand types.