Increment variable with number in variable + PHP - php

Question

I have some variables like this:
$_8 = 0; $_9 = 0; $_10 = 0; $_11 = 0; $_12 = 0; $_13 = 0; $_14 = 0; $_15 = 0; $_16 = 0; $_17 = 0; $_18 = 0; $data = array();
Then I do the following:
$vistoday = $app['db']->fetchAll('SELECT `Datum Bezoek 1` FROM `psttodo-uit` WHERE CAST(`Datum Bezoek 1` AS DATE) = CURRENT_DATE AND PB = 1');
foreach($vistoday as $v){
$date = strtotime($v['Datum Bezoek 1']);
$hours = (int)date('h', $date);
$minutes = (int)date('i', $date);
if($minutes > 30)
{
$hours = $hours + 1;
$count = ${"_" . $hours} + 1;
$data[$hours] = $count;
}
else
{
$data[$hours] = ${"_" . $hours}+1;
}
}
These are the dates I pull from the database:
2014-02-27 08:25:34
2014-02-27 08:50:34
2014-02-27 08:55:34
When I output $data I get this:
array (size=2)
8 => int 1
9 => int 1
But Normally the value of key 9 should be 2. So he doesn't increment, he just adds 1 to nothing. Can somebody help me with this?

Answer 1

Yoг don't need variables like $_8
foreach($vistoday as $v){
$date = strtotime($v['Datum Bezoek 1']);
$hours = (int)date('h', $date);
$minutes = (int)date('i', $date);
$hours = round($hours + $minutes / 61); // if $minutes > 30 ceil else floor
$data[$hours] = isset($data[$hours]) ? $data[$hours] + 1 : 1;
}