Select input field options being added outside select field

I am building out a dynamic dropdown field that gets populated with all the “Saturdays” during a 3 month period. The dropdown is being populated correctly but I am getting duplicate ‘options’ added after the closing </select> input. I don’t know what could be causing this. Below in the Javascript when I console.log(formatted); the values only appear ONCE in the Chrome console.

WordPress, Contact Form 7
Dev: Laragon localhost

<select name="dates" class="wpcf7-form-control wpcf7-select wpcf7-validates-as-required span6 dates" aria-required="true" aria-invalid="false">
    <option value="0">Saturday, June 18</option>
    <option value="1">Saturday, June 25</option>
    <option value="2">Saturday, July 2</option>
    <option value="3">Saturday, July 9</option>
    <option value="4">Saturday, July 16</option>
    <option value="5">Saturday, July 23</option>
    <option value="6">Saturday, July 30</option>
    <option value="7">Saturday, August 6</option>
    <option value="8">Saturday, August 13</option>
    <option value="9">Saturday, August 20</option>
    <option value="10">Saturday, August 27</option>
</select>
// HERE'S the issue - Duplicate options added to my page
<option value="0">Saturday, June 18</option>
<option value="1">Saturday, June 25</option>
<option value="2">Saturday, July 2</option>
<option value="3">Saturday, July 9</option>
<option value="4">Saturday, July 16</option>
<option value="5">Saturday, July 23</option>
<option value="6">Saturday, July 30</option>
<option value="7">Saturday, August 6</option>
<option value="8">Saturday, August 13</option>
<option value="9">Saturday, August 20</option>
<option value="10">Saturday, August 27</option>

Contact Form 7

[select* dates class:span6 class:dates "Sat, Jun 04"]

Javascript

jQuery(document).ready(function($) {
// Date object
var date = new Date();
var year = date.getFullYear();
var this_month = date.getMonth();
var this_day = date.getDate();
var num_months = 3;
// Select input
var select = $('.contact .dates');
select.find('option').remove();

// 3 months of Saturdays
let index = 0;
for (var i = 0; i < num_months; i++) {
    var cur_month = this_month + i;
    // Loop through each day of the month
    for (var j = 0; j <= new Date(year, cur_month, 0).getDate(); j++) {    
        var date = new Date(year, cur_month, j);
        // Find Saturdays and append option to select input
        if (date.getDay() == 6){
            let day = "Saturday, ";
            let dayNum = date.getDate();
            let month = date.toLocaleString('default', { month: 'long' });
            // Don't include past Saturdays for the current month
            if (dayNum<this_day && date.getMonth()==this_month){
                continue;
            }
            let formatted = day + month + " "+ dayNum;
            //let value = date.toString('dddd, MMMM ,yyyy');
            select.append($('<option></option>').attr('value', index).text(formatted));
            index += 1;
            console.log(formatted); // This only outputs once NOT twice
        } 
    };
}
});