如何在计算日期之间的差异后为每个日期分配价格？ （date_diff）

Question

i am using the following code(based on this http://goo.gl/5HhSx) to calculate the difference between dates:

<?php
$date1 = '2012-03-29';
$date2 = '2012-04-02';
$datetime1 = date_create($date1);
$datetime2 = date_create($date2);
$interval = date_diff($datetime1, $datetime2);
echo $interval->format('%a days');
?>

The difference is 4 days.March has a fixed price(30€/day) and April has another(40€/day). Is there a way to sum the whole price? Three days until the end of march and another two from april? How can i add them correctly? Any help would be appreciated. Thanks.

Answer 1

For your exact example this works:

$date1 = '2012-03-29';
$dateBoundary = substr($date1, 0, 8).date('t', strtotime($date1));
$date2 = '2012-04-02';
$marchPrice = 30;
$aprilPrice = 40;
$datetime1 = date_create($date1);
$datetime1Boundary = date_create($dateBoundary);
$datetime2 = date_create($date2);
$interval1 = date_diff($datetime1, $datetime1Boundary);
$interval2 = date_diff($datetime1Boundary, $datetime2);
$totalPrice = ($interval1->format('%d') * $marchPrice) + ($interval2->format('%d') * $aprilPrice);
echo number_format($totalPrice, 2);

You can of course extrapolate the idea for periods which span multiple months.