my-website/static/scripts/updatecopyrightyear.js

"use strict";

{
    const copyrightYearElement = document.getElementById("footer-copyrightyear");

    if (copyrightYearElement) {
        const currentYearAsStr = new Date().getFullYear().toString();

        copyrightYearElement.innerText = currentYearAsStr;
        copyrightYearElement.dateTime = currentYearAsStr;
    }
    else
        console.error("Could not find the footer entry for the year of the copyright notice.");
}