In PHP, you can get the current Date and Time by using the function date():
date() OR date('Y-m-d H:i:s')
Manipulating Date/Time is very easy in PHP and you can easily add something to this, like add hours, days, minutes using function strtotime():
date('Y-m-d H:i:s', strtotime('4 minute'));
date('Y-m-d H:i:s', strtotime('6 day'));
date('Y-m-d H:i:s', strtotime('1 hour'));
Also, a short cut way of doing the same is using the + operator. Like the following:
$timestamp = strtotime('4:29') + 60*60; // Adding One Hour
$time = date('H:i', $timestamp);
echo $time;// This will print 5:29
