Time Calculation

[Pilli]

I have a form where I put in start time and end time
eg

$start= 11:00;
$end=16:30;

What i would like to do is get the total number of hours
eg. total hours between 11:00 and 16:30

I tried

$difference= $end-$start;
echo "$difference";


but I get the answer 5 when it should be 5:30

I think I should be using the date function but not sure how to subtract two times. A point in the right direction would be most appreciated.

[.josh]

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