Very difficult or impossible

Hi, this morning I have seen that the script at pagina:
http://www.teachingonline.it/script/statistiche2.php wasn't working
properly

With this code I estract the day of the week in numeric format

$data=$record['Data_Visita']; // year-month-day date format
$anno=substr($data,1,4);
$mese=substr($data,6,2);
$giorno=substr($data,8,2);
$utime = mktime (0,0,0, $mese,$giorno,$anno,-1);
$weekday=date('w',$utime);
if ($weekday==0)
$weekday=7; // days from 1 to 7 (in Italian) echo $weekday;

This code has worked correctly before sept 30, after this day, I should
have had weekday=6, then 7, then 1 again, but after 5 I get 3, and so on

What is the problem?

Francesco

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