Return Multiple Dates for Script on Page

Question

I am using the following script to return a date for a web page, however when using this script twice on a page only one date is returned (even when using different IDs). Should I be using an array for the startDate?

<script>
let startDate = "1 January 2020";
let startDateObj = new Date(startDate);
let recurringDay = 14;
let today = new Date();
var days = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
var months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
let totalDays = Math.floor((today-startDateObj)/(1000 * 60 * 60 * 24));
let daysLeftToRecur = (recurringDay - totalDays%recurringDay) || recurringDay;
let nextDate = new Date(new Date().getTime()+(daysLeftToRecur * 1000 * 60 * 60 * 24));
document.getElementById("displaydate").innerHTML = days[nextDate.getDay()] + " " + nextDate.getDate() + " " + months[nextDate.getMonth()] + " " + nextDate.getFullYear();
</script>