<b id="showtime" class="wel"></b>

JS部分：

function showTime() {
    var show_day = new Array('星期日', '星期一', '星期二', '星期三', '星期四', '星期五', '星期六');
    var time = new Date();
    var year = time.getFullYear();
    var month = time.getMonth() + 1;
    var date = time.getDate();
    var day = time.getDay();
    var hour = time.getHours();
    var minutes = time.getMinutes();
    var second = time.getSeconds();
    /*  month<10?month='0'+month:month;  */
    hour < 10 ? hour = '0' + hour : hour;
    minutes < 10 ? minutes = '0' + minutes : minutes;
    second < 10 ? second = '0' + second : second;
    var now_time = '今天是：' + year + '年' + month + '月' + date + '日' + ' ' + show_day[day] + '';
    document.getElementById('showtime').innerHTML = now_time;
    /* setTimeout("showTime();",1000);  */
}
$(function () {
    showTime();
});