count hours remain between 2 dates with php - php

Question

i have this dates
$dt_occ = mysql_result($info,0,"occ_data");
$dt_occ = strtotime($dt_occ);
$dt_occ = strtotime('+1 day' , $dt_occ);
$dt_unico = date('d/m/Y H:i',$dt_occ);
$dt_il = date('d/m/Y',$dt_occ);
$dt_alle = date('H:i',$dt_occ);
I need to know how many hours remain between now and $dt_unico

Answer 1

Take a look at the DateTime classes, they are much more flexible that strtotime() and date() (IMHO). Something like this will work for you:-
function getDiffInHours(\DateTime $earlierDate, \DateTime $laterDate)
{
$utc = new \DateTimeZone('UTC');
//Avoid side effects
$first = clone $earlierDate;
$second = clone $laterDate;
//First convert to UTC to avoid missing hours due to DST etc
$first->setTimezone($utc);
$second->setTimezone($utc);
$diff = $first->diff($second);
return 24 * $diff->days + $diff->h;
}
Use it like this for example:-
$hours = getDiffInHours(new \DateTime($dt_occ), (new \DateTime($dt_occ))->modify('+ 1 day'));
var_dump($hours); //24

Answer 2

I think this will work for you.
$dt1 = new DateTime($dt_occ);
$dt2 = new DateTime($dt_occ);
$dt2->modify("+1 day");
$interval = $dt2->diff($dt1);
echo $interval->hours;
If you're using PHP5.5 you can simply this a little bit:
$dt1 = new DateTimeImmutable($dt_occ);
$dt2 = $dt1->modify("+1 day");
$interval = $dt2->diff($dt1);
echo $interval->hours;

Answer 3

Since $dt_unico is derived from $dt_occ, which is a timestamp and time() gives the current time, also as a timestamp, subtracting the former from the latter will give the interval between them, in seconds.
Now, an hour is 60*60=3600 seconds, so:
$interval=(time()-$dt_occ)/3600;
Some notes, though:
I assumed that $dt_occ refers to the past. Future dates will give negative results, so if that's the case, switch the subtraction operands.
The above will give a floating point result. For an integral result, use the appropriate rounding function depending on the desired rounding method.