Adding minutes to date time not working properly

Question

I am working on Yii2. In it I am trying to insert data into 3 different stages. i.e. I am using 3 queries one by one to insert different types of data. The data

Answer 1

customize this:

$dt = date('Y-m-d H:i:s');
echo $dt . '<br>'; //now
$min5Later = strtotime('+5 minutes', strtotime($dt));//5 min later from $dt
$min5LaterFormat = date('Y-m-d H:i:s', $min5Later);

$min10Later = strtotime('+10 minutes', strtotime($dt));//10 min later from $dt
$min10LaterFormat = date('Y-m-d H:i:s', $min10Later);

$min15Later = strtotime('+15 minutes', strtotime($dt));//15 min later from $dt
$min15LaterFormat = date('Y-m-d H:i:s', $min15Later);

for ($i = 0; $i <= 2; $i++) {
    $min5Later = strtotime('+5 minutes', strtotime($min5LaterFormat));//5 min later from $min5later
    $min5LaterFormat = date('Y-m-d H:i:s', $min5Later);
    $min10Later = strtotime('+10 minutes', strtotime($min10LaterFormat));//10 min later from $min10later
    $min10LaterFormat = date('Y-m-d H:i:s', $min10Later);
    $min15Later = strtotime('+15 minutes', strtotime($min15LaterFormat));//15 min later from $min15later
    $min15LaterFormat = date('Y-m-d H:i:s', $min15Later);

 echo $min5LaterFormat . ' | ';
 echo $min10LaterFormat . ' | ';
 echo $min15LaterFormat . ' | <br>';
}

output:

2020-05-10 19:19:47
2020-05-10 19:29:47 | 2020-05-10 19:39:47 | 2020-05-10 19:49:47 |
2020-05-10 19:34:47 | 2020-05-10 19:49:47 | 2020-05-10 20:04:47 |
2020-05-10 19:39:47 | 2020-05-10 19:59:47 | 2020-05-10 20:19:47 |