jQuery 日時を表示

$(function(){
	$("要素").text(new Date());
});

@See
http://www.webdlab.com/guide/jquery-new-date/

  var now = new Date();
  var y = now.getFullYear();
  var m = now.getMonth() + 1;
  var d = now.getDate();
  var w = now.getDay();
  var wd = ["日", "月", "火", "水", "木", "金", "土"];
  var h = now.getHours();
  var mi = now.getMinutes();
  var s = now.getSeconds();
	$("要素").text(y + "年" + m + "月" + d + "日" + h + "時" + mi + "分" + s + "秒" + "(" + wd[w] + ")");
});

リアルタイムだと

$(function(){
setInterval(function(){
  var now = new Date();
  var y = now.getFullYear();
  var m = now.getMonth() + 1;
  var d = now.getDate();
  var w = now.getDay();
  var wd = ["日", "月", "火", "水", "木", "金", "土"];
  var h = now.getHours();
  var mi = now.getMinutes();
  var s = now.getSeconds();
	$(".要素").text(y + "年" + m + "月" + d + "日" + h + "時" + mi + "分" + s + "秒" + "(" + wd[w] + ")");
}, 1000);
});