var now = new Date();
var nYear = now.getFullYear();
var nMonth = now.getMonth();
var nDate = now.getDate();

myD       = new Date(nYear, nMonth, nDate - 1);

myYear    = myD.getYear();
myYear4   = (myYear < 2000) ? myYear+1900 : myYear;
myMonth   = myD.getMonth();
myDate    = myD.getDate();

myMess1   = myYear4 + "年" + myMonth + "月" + myDate + "日";
myMess    = "<p class=\"al-l\">更新：" + myMess1 + "</p>";
document.write( myMess );