Date for fines integer

claro · March 2, 2012, 6:06pm

Greetings!

I’m trying to make a formula that computes fine charge in my project.
Here is my simple code.


 $dues =  date_create($row['Datedue']);
 $due= date_format($dues,'Ymd');
 $now =  date("Ymd");
 $cost = $row['Fines'];
 $fine = $now-$due;
									
			if ($fine<=0){
			$fines = 0;
			}else {
                       $fines = $fine * $cost;
                         }

My problem is I want to exclude the saturday and sunday in computing. Is that possible?

wonshikee · March 2, 2012, 6:23pm

So if it’s Sun through Sat between $due and $now, You’d want it to be 5 * $cost?

I would simply iterate from $now till $due, and use date() to check if it’s a saturday/sunday and skip it.

You could also do it mathematically based on the day $now is versus the day $due is, using modulus and some if condition checks, but I would just go with the first suggestion to make it easier on yourself and future maintainability.

claro · March 2, 2012, 6:32pm

Thank you for quick response.I’m not sure if I get it.

Assuming that I borrowed books from our library, and should be returned
after 6 days (excluding sat and sun), beyond that I must pay book fines with $1/day.

What do you mean by 5 * cost. ?
Hope I’m making my statement clear.

wonshikee · March 2, 2012, 6:39pm

What does $row[‘Datedue’] look like?

claro · March 2, 2012, 6:43pm

Its a date(“Y-m-d”) format.

20120303 - 20120229 = 3 * fines.
Now - Due = 3 * fines.

wonshikee · March 2, 2012, 6:47pm

	$due =  strtotime($row['Datedue']);
	$now = time();
	$cost = $row['Fines'];
	$days = 0;
	
	while ($now < $due)
	{
		if (date('N', $now) == 6 || date('N', $now) == 7) continue; # skip sat/sun
		$days++;
		$now = strtotime('+1 Day', $now);
	}

claro · March 2, 2012, 7:03pm

there is an error:

Fatal error: Maximum execution time of 60 seconds exceeded

What does it mean?

wonshikee · March 2, 2012, 7:29pm

That means that loop is causing an infinite loop… hmm…

I see the error in logic.


	$due =  strtotime($row['Datedue']);
	$now = time();
	$cost = $row['Fines']; 
	$days = 0;
	
	while ($now < $due)
	{
		if (!date('N', $now) == 6 && !date('N', $now) == 7) {
			$days++;
		}
		$now = strtotime('+1 Day', $now);
	}

It was basically getting caught because if it was a saturday, it would start the loop over, then $now would still be saturday.

claro · March 2, 2012, 7:47pm

Thank you for the code, but can you explain or just tell something about your code? I’m new in php.
Where can I put my formula in finding the product of fines?
like now-due date = fines. How about the interval of book when borrowed? like when I borrowed book that should be returned after 3 days.

wonshikee · March 2, 2012, 7:49pm

My code replaces all of yours.

If you don’t understand my code, which I was hoping you would, then simply add this after the whole loop.

$fines = $days * $cost;

ParkinT · March 2, 2012, 8:12pm

@wonshikee; You applied a very elegant solution to this problem. I have been away from PHP for a while and was struggling (mentally) between the two different approaches I would have taken.
Your code is concise, clean and effective!
:applause:

wonshikee · March 2, 2012, 8:26pm

Thank you sir.

claro · March 3, 2012, 8:02am

I made this code to understand my problem.


$query = mysql_query("SELECT * FROM tbl_studentbook WHERE id = 3") or die (mysql_error());
	while ($row = mysql_fetch_array($query))
	{
		$bor =   date_create($row['sbook_Borrow']);
		$bor= date_format($bor,'N'); //2012-03-03 sat
		
		$due =   date_create($row['sbook_Due']);
		$due= date_format($due,'N'); //2012-03-18 sun
		$cost = 5;
		
		if ($due == 6){
		$due = $due + 2;
		}if ($due == 7){
		$due = $due + 1;}
		
		//my new due date should be 2012-03-19 monday
		
		$now = date();//assuming today is 2012-03-21 wed
		
		//so I must pay 2 days book fines which cost $1
		$fines = $now - $due;
		$fines = 2 * $cost;
		$totalfines = 10;
	}

Help me more please. thank you.

salathe · March 3, 2012, 12:31pm

Here’s a little function that takes the due date and current date, and (should) return the number of days overdue.


function days_overdue(DateTime $due, DateTime $now)
{
    // Skip to next weekday if on weekend
    if (in_array($due->format('D'), array('Sat', 'Sun'))) {
        $due = clone $due;
        $due->modify('next weekday');
    }

    // Generate period of weekdays between start and end
    $period = new DatePeriod($due, DateInterval::createFromDateString('next weekday'), $now, DatePeriod::EXCLUDE_START_DATE);

    return iterator_count($period);
}

Your code snippet would then look like


    while ($row = mysql_fetch_array($query))
    {
        // ...

        $due = date_create($row['sbook_Due']);
        $now = date_create();

        $overdue = days_overdue($due, date_create());

        // so I must pay $overdue days book fines which cost $cost dollars per day
        $cost = 5;
        $fines = $overdue_days * $cost;

        // ...
    }