How to create a proper calculation of a due date in a dynamic manner in laravel - laravel

Question

I been analyzing the proper calculation of the duedate for my app. I am working with a lending app where I need to display the due date for the borrower.
let say the approved date of their loan is 2019-10-27 and today is 11-5-2019. the payment scheme is dynamic. depending on what the admin set. in this example, the payment scheme weekly so I just need to say;
$duedate = date('M d Y', strtotime($loan_application->date_approval. ' + '.$loan_application->scheme->num_days.' days') );
from my example above the due date is supposedly on Nov 3, 2019. Now how can I make it say that the next due date is on Nov 10, 2019?
I really tried to analyze, here's my thought.
I get the difference between the approval date and NOW()
$diff = Carbon::createFromTimestamp(strtotime($loan_application->date_approval))->diff(Carbon::now())->days;
now I compared the $diff with $loan_application->scheme->num_days. so let say the $diff=9 and $loan_application->scheme->num_days = 7
now I created the condition
if ($diff > $loan_application->scheme->num_days) {
//should display
Nov 10, 2019
//because the current date is already Nov 5
}
and after Nov 10, + 7 days again, and + 7 days again and so on.
here is the complete code I already have;
$dateApproved = Carbon::parse($loan_application->date_approval)->toFormattedDateString();
$now = Carbon::today('M d Y');
$duedate = date('M d Y', strtotime($loan_application->date_approval. ' + '.$loan_application->scheme->num_days.' days') );
$diff = Carbon::createFromTimestamp(strtotime($loan_application->date_approval))->diff(Carbon::now())->days;
$numOfScheme = $loan_application->loanDuration->num_days / $loan_application->scheme->num_days;
if ($diff > $loan_application->scheme->num_days) {
}
I hope you understand my question. Please help. Thank you so much in advance.
this will add number of days from payment scheme. in my example 7 days. but how can I tell my code that today is already 2 days late, add additional 7 days

Answer 1

It took some time but I understood your question.
$date_approval = Carbon::createFromTimestamp(strtotime($loan_application->date_approval));
$scheme_numdays = $loan_application->scheme->num_days;
$days = (intdiv($date_approval->diff(Carbon::now())->days , $scheme_numdays) + 1) * $scheme_numdays
$due_date = $date_approval->addDays($days)->format('M d Y');
intdiv is just php's integer division.