如何在计算日期之间的差异后为每个日期分配价格？ （date_diff）

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.

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.

Extract the month out of the date like this:

SELECT MONTH('8/14/04') as "Month";

for each date between '2012-03-29' and '2012-04-02' and then update the table accordingly. In case, you want to add up the sum then use a stored procedure -declare a variable 'sum' intitialized to zero and add by using switch cases like : CASE '04' then sum+=30 , CASE '03' then sum+=20. Or,you can use an aggregate function too in your procedure for calculating.

Brief logic on achieving the target result.

  1. Keep an array of price list for the months,
  2. find the difference of months between the dates.
  3. In a loop for the month take the day difference from the last day for that month and multiply with the corresponding price from the array.
  4. Inside the loop sum all this calculation into an total amount variable.

Refer the mktime() and Date() functions