或者只是简单地执行以下代码:

    <script>
        time = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            m = checkTime(m);
            s = checkTime(s);
            document.getElementById('txt_clock').innerHTML = h + ":" + m + ":" + s;     
            var t = setTimeout(function(){time()}, 0);
        }

        time2 = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            m = checkTime(m);
            s = checkTime(s);
            if (h>12) {
                document.getElementById('txt_clock_stan').innerHTML = h-12 + ":" + m + ":" + s;
            }               
            var t = setTimeout(function(){time2()}, 0);
        }

        time3 = function() {
            var today = new Date();
            var h = today.getHours();
            var m = today.getMinutes();
            var s = today.getSeconds();
            if (h>12) {
                document.getElementById('hour_line').style.width = h-12 + 'em'; 
            }
            document.getElementById('minute_line').style.width = m + 'em';  
            document.getElementById('second_line').style.width = s + 'em';  
            var t = setTimeout(function(){time3()}, 0);
        }

        checkTime = function(i) {
            if (i<10) {i = "0" + i};  // add zero in front of numbers < 10
            return i;
        }           
    </script>

<h1 id="clock_display" class="text-center" style="font-size:40px; color:#ffffff">[CLOCK TIME DISPLAYS HERE]</h1>



<script>
            var AM_or_PM = "AM";

            function startTime(){

                var today = new Date();
                var h = today.getHours();
                var m = today.getMinutes();
                var s = today.getSeconds();

                h = twelve_hour_time(h);
                m = checkTime(m);
                s = checkTime(s);



                document.getElementById('clock_display').innerHTML =
                    h + ":" + m + ":" + s +" "+AM_or_PM;
                var t = setTimeout(startTime, 1000);

            }

            function checkTime(i){

                if(i < 10){
                    i = "0" + i;// add zero in front of numbers < 10
                }
                return i;
            }

            // CONVERT TO 12 HOUR TIME. SET AM OR PM
            function twelve_hour_time(h){

                if(h > 12){
                    h = h - 12;
                    AM_or_PM = " PM";
                }
                return h;

            }

            startTime();

        </script>

下面是一种使用regex的方法:

console.log(新日期(“7/10/2013 20:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”)) console.log(新日期(“7/10/2013 01:12:34”).toLocaleTimeString () .replace (/ ((\ d) +: \ d {2}) (: \ [d] {2 })(.*)/, "$ 1美元3”))

这将创建3个匹配组:

([\d]+:[\d]{2}) -小时:分钟 (:[\d]{2}) -秒 (.*) -空格和时段(时段是AM/PM的正式名称)

然后显示第1组和第3组。

警告:toLocaleTimeString()可能会根据区域/位置表现不同。

函数formatAMPM(date) { var hours = date.getHours(); var minutes = date.getMinutes(); Var ampm =小时>= 12 ?'pm': 'am'; 小时=小时% 12; 小时=小时?时长:12小时;//小时'0'应该是'12' 分钟=分钟< 10 ?'0'+minutes: minutes; var strTime = hours + ':' + minutes + ' + ampm; 返回strTime; ｝ console.log (formatAMPM(新日期));

使用dateObj。toLocaleString([地区[选项]])

选项1 -使用区域设置

var date = new Date();
console.log(date.toLocaleString('en-US'));

选项2 -使用选项

var options = { hour12: true };
console.log(date.toLocaleString('en-GB', options));

注:支持除safari atm以外的所有浏览器

下面是解决方案

var d = new Date();
var amOrPm = (d.getHours() < 12) ? "AM" : "PM";
var hour = (d.getHours() < 12) ? d.getHours() : d.getHours() - 12;
return   d.getDate() + ' / ' + d.getMonth() + ' / ' + d.getFullYear() + ' ' + hour + ':' + d.getMinutes() + ' ' + amOrPm;