Recurring - Every month processing?

godwheel

Hi guys:

Maybe one of you can help me.

I'm writing a recurring payment software package, but I'm encountering a problem. I want to be able to bill a customer EVERY month. The problem however, is months with 31 days and February.

I thought of using mktime and say a person registers on the 31st of january, to simply use:

$samplemonth = mktime(0, 0, 0, 1, 31, 2006);
$samplenextmonth = mktime(0, 0, 0, 2, 31, 2006);

mktime will make the next billing March 1st, 2006 by default. However, if someone registers

$samplemonth = mktime(0, 0, 0, 1, 30, 2006);
$samplenextmonth = mktime(0, 0, 0, 2, 30, 2006);

It will also give back March 1st, 2006. Meaning, the invididuals who registered on the 30th loose a day.

What is the best way to go about this?

I also thought about just charging every 30 days instead of every month, but I'm not sure that is the wisest way. How do credit cards do it?

Thanks for any help you can provide.

godwheel

By the way. A couple of examples:

I joined Netflix on November 14

I get billed:
January 14
February 14
March 14
April 14

I want to do the same exact thing.

However, the problem comes when you see:

January 31
February ??
March 31
April ?? (30?)

See my predicament?

Thanks in advance!

etully

In your Netflix example, the solution is easy because the billing date is always 14. That way, when your script runs, it says, "What day of the month is this?" Ok, find all customers whose billing date = 14 and send email / print invoice / whatever.

I think the reason you're having a problem is, it's not so easy to put 28/30/31 as the billing date. (Meaning, sometimes bill on the 28th, sometimes the 30th, sometimes the 31st.)

So you need to have some way of indicating that this customer's billing date isn't a fixed date like "14" but instead is a code that signifies, "End of the Month".

If the billing date in the database is an integer field, you might specify "End of Month" by inserting 99 or zero or something like that.

Once you have some method of specifying that a customer's billing date is to be the end of the month, then you might write some code like this:

$num_days_in_this_month = date("t",time());
$todays_day_of_the_month = date("j",time());
if ($num_days_in_this_month == $todays_day_of_the_month) {
// Today is the last day of the month
$query = "select email from customers where billing_date=99";
}

The beauty of this solution is that if you WANTED some customer to be billed on the 28th of every month, then you can enter "28" for their billing date... but if you want them billed at the END of the month, then you enter "99" for their billing date.

godwheel

That is a very slick solution to my problem.

Thanks I'll give that a try :evilgrin: