voproser

$oldTime = strtotime('10:30');
$newTime = date("H:i", strtotime('+10 minutes', $oldTime));

$minutesToAdd = 10;

$time = new DateTime('2019-10-17 10:30');
$time->add(new DateInterval('PT' . $minutesToAdd . 'M'));
$newTime = $time->format('H:i');

echo $newTime;

$date = '2019-10-17 10:30:00';
$currentDate = strtotime($date);
$futureDate = $currentDate+(10*60); //ну вы поняли
$formatDate = date("Y-m-d H:i:s", $futureDate);

$time = new \DateTime('10:30');
$time->add(new \DateInterval('PT10M'));
echo $time->format('H:i');

set @i := -1;
update tablename set id = (@i := @i+1 ) order by id;