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<?php
$next_month=date("m")+1;
$first_day_in_next_month_in_seconds=mktime(0,0,0,($next_month >12 ? 1 : $next_month),1,($next_month>12 ? (date("Y")+1) : date("Y")));
$first_weekday=date("w",$first_day_in_next_month_in_seconds);
$seconds_per_day=86400;
switch ($first_weekday)
{
	case 5 :	$next_friday=$first_day_in_next_month_in_seconds;
				break;// es ist freitag
	case 6 :	$next_friday=$first_day_in_next_month_in_seconds+(6*$seconds_per_day);
				break;
	case 0 :	$next_friday=$first_day_in_next_month_in_seconds+(5*$seconds_per_day);
				break;
	case 1 :	$next_friday=$first_day_in_next_month_in_seconds+(4*$seconds_per_day);
				break;
	case 2 :	$next_friday=$first_day_in_next_month_in_seconds+(3*$seconds_per_day);
				break;
	case 3 :	$next_friday=$first_day_in_next_month_in_seconds+(2*$seconds_per_day);
				break;
	case 4 :	$next_friday=$first_day_in_next_month_in_seconds+$seconds_per_day;
				break;
}
echo "Das Datum für den nächsten Freitag im nächsten Monat ist: <b>".date("d.m.Y",$next_friday)."</b>";
?>

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<?php
$found=false;
$i=1;
while($i<=7 && false===$found)
{
    if(date("w",$stamp)==5)
        $found=true;
}
?>

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strtotime('next month')