function getDateTime() {
  var now = new Date();
  var year = now.getFullYear();
  var month = now.getMonth() + 1;
  var day = now.getDate();

  if (month.toString().length == 1) {
    month = '0' + month;
  }
  if (day.toString().length == 1) {
    day = '0' + day;
  }

  var hours = now.getHours();
  var minutes = now.getMinutes();
  var ampm = hours >= 12 ? 'pm' : 'am';
  hours = hours % 12;
  hours = hours ? hours : 12;
  minutes = minutes < 10 ? '0' + minutes : minutes;
  var timewithampm = hours + ':' + minutes + ' ' + ampm;

  var dateTime = monthNames[parseInt(month) - 1] + ' ' + day + ' ' + year + ' ' + timewithampm;
  return dateTime;
}

<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>

如果你把时间设置为字符串，输入var myTime = "15:30" 然后您可以使用下面的代码来获取am pm。

var hour = parseInt(myTime.split(":")[0]) % 12;
var timeInAmPm = (hour == 0 ? "12": hour ) + ":" + myTime.split(":")[1] + " " + (parseInt(parseInt(myTime.split(":")[0]) / 12) < 1 ? "am" : "pm");

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 >

如果你不需要打印上午/下午，我发现以下内容很好很简洁:

var now = new Date();
var hours = now.getHours() % 12 || 12;  // 12h instead of 24h, with 12 instead of 0. 

这是基于@bbrame的回答。

我的建议是使用moment js进行日期和时间操作。

https://momentjs.com/docs/#/displaying/format/

console.log(时刻)。格式(“hh: mm ')); < script src = " / / cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js " > < /脚本>