<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>

函数startTime() { const today = new Date(); let h = today.getHours(); let m = today.getMinutes(); let s = today.getSeconds(); Var子午线= h >= 12 ?pm: am; H = H % 12; H = H ?H: 12; M = M < 10 ?“0”+ m: m; S = S < 10 ?“0”+ s: s; var strTime = h +“:”+ m +”:“+ s + " " +子午线; . getelementbyid(的时间)。innerText = strTime; setTimeout(开始时间,1000); ｝ 开始时间(); < h1 id = '时间' > < / h1 >

试试这个

      var date = new Date();
      var hours = date.getHours();
      var minutes = date.getMinutes();
      var seconds = date.getSeconds();
      var ampm = hours >= 12 ? "pm" : "am";

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>

<script>
var todayDate = new Date();
var getTodayDate = todayDate.getDate();
var getTodayMonth =  todayDate.getMonth()+1;
var getTodayFullYear = todayDate.getFullYear();
var getCurrentHours = todayDate.getHours();
var getCurrentMinutes = todayDate.getMinutes();
var getCurrentAmPm = getCurrentHours >= 12 ? 'PM' : 'AM';
getCurrentHours = getCurrentHours % 12;
getCurrentHours = getCurrentHours ? getCurrentHours : 12; 
getCurrentMinutes = getCurrentMinutes < 10 ? '0'+getCurrentMinutes : getCurrentMinutes;
var getCurrentDateTime = getTodayDate + '-' + getTodayMonth + '-' + getTodayFullYear + ' ' + getCurrentHours + ':' + getCurrentMinutes + ' ' + getCurrentAmPm;
alert(getCurrentDateTime);
</script>