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如何以12小时的AM/PM格式显示JavaScript日期时间？

javascriptdatetimedatetimeformat
489
你如何在JavaScript中以12小时制(AM/PM)显示日期和时间？
3
不要浪费时间，https://dev59.com/-Gox5IYBdhLWcg3w6oj0#17538193 这个方法可行。 - Ritesh
2
@Ritesh 警告：toLocaleTimeString() 的行为可能因地区/位置而异。 量好再切。 - Abandoned Cart
@AbandonedCart 这真的是一句俗语吗？ - gilbert-v
1
@gilbert-v 在切割木材之前，应该仔细检查测量数据的准确性；否则可能需要重新切割，浪费时间和材料。不过，那个问题可能更适合在谷歌上提问。 - Abandoned Cart
2
我将永远不会习惯在 JavaScript 中尝试处理简单日期有多么麻烦。 - ashleedawg
33个回答
2

如果有人正在寻找一个 1-liner：

const formatAMPM = date => `${(date.getHours() % 12) || 12}:${date.getMinutes().toString().padStart(2, '0')} ${date.getHours() < 12 ? 'AM' : 'PM'}`

或者更易读的三行代码（如果您的浏览器中没有padStart）：

const formatAMPM = (date) => {
  let minutes = date.getMinutes()
  minutes = minutes < 10 ? '0' + minutes : minutes
  return `${(date.getHours() % 12) || 12}:${minutes} ${date.getHours() < 12 ? 'AM' : 'PM'}`
}
1
你可以使用这个简单的代码确定上午或下午。

var today=new Date();
var noon=new Date(today.getFullYear(),today.getMonth(),today.getDate(),12,0,0);
var ampm = (today.getTime()<noon.getTime())?'am':'pm';
1

function formatTime( d = new Date(), ampm = true ) 
{
    var hour = d.getHours();
    
    if ( ampm )
    {
        var a = ( hour >= 12 ) ? 'PM' : 'AM';
        hour = hour % 12;
        hour = hour ? hour : 12; // the hour '0' should be '12'  
    }

    var hour    = checkDigit(hour);  
    var minute  = checkDigit(d.getMinutes());
    var second  = checkDigit(d.getSeconds());
  
    // https://dev59.com/XHM_5IYBdhLWcg3wXx5N
    return ( ampm ) ? `${hour}:${minute}:${second} ${a}` : `${hour}:${minute}:${second}`;
}

function checkDigit(t)
{
  return ( t < 10 ) ? `0${t}` : t;
}

document.querySelector("#time1").innerHTML = formatTime();
document.querySelector("#time2").innerHTML = formatTime( new Date(), false );
<p>ampm true:   <span id="time1"></span> (default)</p>
<p>ampm false:  <span id="time2"></span></p>

1
尝试这个。
      var date = new Date();
      var hours = date.getHours();
      var minutes = date.getMinutes();
      var seconds = date.getSeconds();
      var ampm = hours >= 12 ? "pm" : "am";
这是不正确的。小时数可能大于12。 - Utsav T
当时间为下午12点时，变量ampm将是“pm”。因此，下午12:00到晚上11:00的小时数将是12到23，存储“pm”值，而对于其他时间，变量ampm将存储“am”值。希望您能理解。 - Md. Juyel Rana
嗨Juyel！确实，当小时数大于12时，值应该是PM。但问题是“如何在JavaScript中以12小时AM / PM格式显示日期时间？” - 您需要帮助OP将整个时间转换为AM / PM格式。例如，14:30将变为2:30 PM。 - Utsav T
0
<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>
0

{new Date(progress.position * 1000).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }).substring(0,5)}

0

var d = new Date();
var hours = d.getHours() % 12;
  hours = hours ? hours : 12;
    var test = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][(d.getMonth() + 1)] + " " + 
    ("00" + d.getDate()).slice(-2) + " " + 
    d.getFullYear() + " " + 
    ("00" + hours).slice(-2) + ":" + 
    ("00" + d.getMinutes()).slice(-2) + ":" + 
    ("00" + d.getSeconds()).slice(-2) + ' ' + (d.getHours() >= 12 ? 'PM' : 'AM'); 
    
document.getElementById("demo").innerHTML = test;
<p id="demo" ></p>

0
   const formatAMPM = (date) => {
    try {
      let time = date.split(" ");
      let hours = time[4].split(":")[0];
      let minutes = time[4].split(":")[1];
      hours = hours || 12;
      const ampm = hours >= 12 ? " PM" : " AM";
      minutes = minutes < 10 ? `${minutes}` : minutes;
      hours %= 12;
      const strTime = `${hours}:${minutes} ${ampm}`;
      return strTime;
    } catch (e) {
      return "";
    }
  };

const startTime = "2021-12-07T17:00:00.073Z"
formatAMPM(new Date(startTime).toUTCString())
0

这是我的解决方案

function getTime() {
var systemDate = new Date();
var hours = systemDate.getHours();
var minutes = systemDate.getMinutes();
var strampm;
if (hours >= 12) {
    strampm= "PM";
} else {
    strampm= "AM";
}
hours = hours % 12;
if (hours == 0) {
    hours = 12;
}
_hours = checkTimeAddZero(hours);
_minutes = checkTimeAddZero(minutes);
console.log(_hours + ":" + _minutes + " " + strampm);
}

function checkTimeAddZero(i) {
if (i < 10) {
    i = "0" + i
}
return i;
}
0
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;
}
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