$per12 = strftime('%b',mktime(0,0,0,$mo,$da,$yr));
$per11 = strftime('%b',mktime(0,0,0,$mo-1,$da,$yr));
$per10 = strftime('%b',mktime(0,0,0,$mo-2,$da,$yr));
$per12 = strftime('%b',mktime(0,0,0,$mo,$da,$yr));
$per11 = strftime('%b',mktime(0,0,0,$mo-1,$da,$yr));
$per10 = strftime('%b',mktime(0,0,0,$mo-2,$da,$yr));