Creating date array for future payments

Question

I have 3 dates: Present date = 11/7/2018

Start date = 11/14/2018

End date = 11/13/2019

Payment is every 3 months. If the payment type is 'Advance', rent is due on the 14th.

Array = [8,89,92,92]

If payment type = 'Arrears', rent is due on the 13th.

Since, the start date is on 11/14, the payments are on 2/13/2019, 5/13/2019, 8/13/2019 and 11/13/2019.

 Array = [99,88,91,91]

I need to create an array of number of days between Present date and the First payment date. What i tried:

const start = "11/14/2018";
const end = "05/13/2021 ";

const dates = [];

const mstart = moment(start, "MM/DD/YYYY");
const mend = moment(end, "MM/DD/YYYY");


    for (var i = 0; mstart <= mend; i++) {
    if (selectedPayType === "A") {
    let Q = mstart.clone();
    mstart.add(3, 'months');
    const daysInMonth = mstart.diff(Q, 'days');
    dates.push(daysInMonth);
    }
        if (selectedPayType === "B") {
     //code goes here....
    }
    console.log(dates);

I am confused on the second part and don't know how to define that. Any help is appreciated. Thank you.

Answer 1

I did it the following way by adding 3 months to the date since the payment is always 3 months from now.

 if (selectedPayType === "B") {
             startDateC.add(3, 'months');
             startDateC.subtract(1,'days');
             var futureLease = startDateC.diff(presentDateC, 'days');
             array.unshift(futureLease);
             for (var i = 1; i < array.length; i++) {
                 (array[i] += array[i - 1]);
             }
          console.log(array);
         }