my $string_time = localtime(time());
my $yesterday   = localtime(time()-24*60*60);
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) 
    = localtime(time);
print "$string_time\n$yesterday\n";
printf "%02d:%02d:%02d %02d/%02d/%4d\n", $hour, $min, $sec, $mday, $mon+1, $year+1900;