date = new Date();
y = date.getFullYear();
m = date.getMonth() + 1;
d = date.getDate();

if (m < 10) { m = "0" + m; }
if (d < 10) { d = "0" + d; }

document.write("本日は" + y + "年" + m + "月" + d + "日です。");