Function to format and display the time from a UNIX timestamp does not work in Safari Browser

Question

This JavaScript code do not work in Safari Browser but works well in other browser. Code returns time or date from timestamp value but not works in safari browser. In safari code returns: aN.aN.aN or aN:aN related issue

// Get all elements with class "time" and "date"
const timeElements = document.getElementsByClassName("time");
const dateElements = document.getElementsByClassName("date");

// Function to format and display the time from a UNIX timestamp
function formatTimeElement(element) {
  // Extract UNIX timestamp from the element's innerHTML
  let unixTimeStamp = element.innerHTML;

  // Convert UNIX timestamp to a JavaScript Date object
  let dateObject = new Date(unixTimeStamp * 1000);

  // Extract hours and minutes, ensuring leading zeros if needed
  let hours = "0" + dateObject.getHours();
  let minutes = "0" + dateObject.getMinutes();

  // Create formatted time string (HH:MM)
  let timeElement = hours.substr(-2) + ":" + minutes.substr(-2);

  // Update the element's content with the formatted time
  element.innerHTML = timeElement;
}

// Function to format and display the date from a UNIX timestamp
function formatDateElement(element) {
  // Extract UNIX timestamp from the element's innerHTML
  let unixTimeStamp = element.innerHTML;

  // Convert UNIX timestamp to a JavaScript Date object
  let dateObject = new Date(unixTimeStamp * 1000);

  // Extract day, month, and year, ensuring leading zeros if needed
  let day = "0" + dateObject.getDate();
  let month = "0" + (dateObject.getMonth() + 1);
  let year = dateObject.getFullYear().toString();

  // Create formatted date string (DD.MM.YY)
  let dateElement =
    day.substr(-2) + "." + month.substr(-2) + "." + year.slice(-2);

  // Update the element's content with the formatted date
  element.innerHTML = dateElement;
}

// Loop through each element with class "time" and format the time
for (element of timeElements) {
  formatTimeElement(element);
}

// Loop through each element with class "date" and format the date
for (element of dateElements) {
  formatDateElement(element);
}

Safari: Safari

Chrome: Chrome