index.html

<link rel="stylesheet" href="style.css">
<script async
  src="https://cse.google.com/cse.js?cx=000888210889775888983:y9tkcjel090"></script>
<div class="gcse-searchbox"></div>
<div class="gcse-searchresults"></div>

<script>
const mySearchStartingCallback = (gname, query) => {
  const dayOfWeek = new Date().getDay();
  console.log(dayOfWeek);
  var days = {
        "0": "Sunday",
        "1": "Monday",
        "2": "Tuesday",
        "3": "Wednesday",
        "4": "Thursday",
        "5": "Friday",
        "6": "Saturday"
    };

    return query + ' ' + days[dayOfWeek];
};
// Install the callback.
window.__gcse || (window.__gcse = {});
  window.__gcse.searchCallbacks = {
    image: {
      starting: mySearchStartingCallback,
    },
    web: {
      starting: mySearchStartingCallback,
    },
};
</script>