Try to parse() it first:
$date = Carbon::parse($dateTime)
->addSeconds($seconds)
->format('Y-m-d H:i:s');
CarbonInterval::seconds(90060)->cascade()->forHumans();
You can use:
----------------
$minutes = 1510;
$hours = intdiv($minutes, 60).':'. ($minutes % 60);
!!! This only works with php >= v7.xx
Previous answer:
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$minutes = 1510;
$hours = floor($minutes / 60).':'.($minutes - floor($minutes / 60) * 60);
CarbonInterval::seconds(90060)->cascade()->forHumans();