today.getDate works on other days except on Sunday

September 25, 2022

Example of this code that works normally at a specified date, which is a Saturday.

weeks=["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"];
  var today = new Date("September 24, 2022 01:15:00"); 
  document.getElementById("current-day").innerHTML=weeks[today.getDay()-1];

<h1 id="current-day"></h1>

As stated in my title above, this code works on other days except only on Sundays, it just says Undefined, why is that?

weeks=["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"];
  var today = new Date("September 25, 2022 01:15:00");
  document.getElementById("current-day").innerHTML=weeks[today.getDay()-1];

<h1 id="current-day"></h1>

>Solution :

Your code logic looks fine but the weeks array should starts with Sunday and avoid using negative 1 with getDay method.

const weeks = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
const today = new Date("September 25, 2022 01:15:00");
document.getElementById("current-day").innerHTML = weeks[today.getDay()];