FreePhoenix888 · October 2, 2020 09:56
diff --git a/getSecondsFromToday.js b/getSecondsFromToday.js
 function getSecondsToday() {
  let now = new Date();

  let today = new Date(now.getFullYear(), now.getMonth(), now.getDate());

  let diff = now - today; // разница в миллисекундах
  return Math.round(diff / 1000); // получаем секунды
 }

 alert( getSecondsToday() );
	function getSecondsToday() {
	let now = new Date();

	let today = new Date(now.getFullYear(), now.getMonth(), now.getDate());

	let diff = now - today; // разница в миллисекундах
	return Math.round(diff / 1000); // получаем секунды
	}

	alert( getSecondsToday() );