如何以12小时AM / PM格式显示JavaScript日期时间?

2020/10/03 06:01 · javascript ·  · 0评论

如何以12小时格式(AM / PM)显示JavaScript日期时间对象?

function formatAMPM(date) {
  var hours = date.getHours();
  var minutes = date.getMinutes();
  var ampm = hours >= 12 ? 'pm' : 'am';
  hours = hours % 12;
  hours = hours ? hours : 12; // the hour '0' should be '12'
  minutes = minutes < 10 ? '0'+minutes : minutes;
  var strTime = hours + ':' + minutes + ' ' + ampm;
  return strTime;
}

console.log(formatAMPM(new Date));

如果您只想显示小时数,那么..

var time = new Date();
console.log(
  time.toLocaleString('en-US', { hour: 'numeric', hour12: true })
);  

输出:7 AM

如果您还希望显示分钟,则...

var time = new Date();
console.log(
  time.toLocaleString('en-US', { hour: 'numeric', minute: 'numeric', hour12: true })
);

输出:7:23 AM

您也可以考虑使用类似date.js的内容

<html>
<script type="text/javascript" src="http://www.datejs.com/build/date.js"></script>

<script>
   (function ()
   {
      document.write(new Date().toString("hh:mm tt"));
   })();
</script>
</html>

这是使用正则表达式的方法:

console.log(new Date('7/10/2013 20:12:34').toLocaleTimeString().replace(/([\d]+:[\d]{2})(:[\d]{2})(.*)/, "$1$3"))
console.log(new Date('7/10/2013 01:12:34').toLocaleTimeString().replace(/([\d]+:[\d]{2})(:[\d]{2})(.*)/, "$1$3"))

这将创建3个匹配的组:

  • ([\d]+:[\d]{2}) -小时:分钟
  • (:[\d]{2}) -秒
  • (.*) -空间和期间(期间是AM / PM的正式名称)

然后显示第一组和第三组。

警告:toLocaleTimeString()的行为可能因地区/位置而异。

如果您不需要打印上午/下午,我发现以下内容简洁明了:

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

这是基于@bbrame的答案。

据我所知,没有扩展和复杂编码的最佳方法是这样的:

     date.toLocaleString([], { hour12: true});

Javascript AM / PM格式

<!DOCTYPE html>
<html>
<body>
    <p>Click the button to display the date and time as a string.</p>

    <button onclick="myFunction()">Try it</button>
    <button onclick="fullDateTime()">Try it2</button>
    <p id="demo"></p>
    <p id="demo2"></p>
    <script>
        function myFunction() {
            var d = new Date();
            var n = d.toLocaleString([], { hour: '2-digit', minute: '2-digit' });
            document.getElementById("demo").innerHTML = n;
        }
        function fullDateTime() {
            var d = new Date();          
            var n = d.toLocaleString([], { hour12: true});
            document.getElementById("demo2").innerHTML = n;
        }
    </script>
</body>
</html>

我发现此检查出此问题。

如何在不显示秒的情况下使用.toLocaleTimeString()?

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(moment().format('hh:mm a'));
<script src="//cdnjs.cloudflare.com/ajax/libs/moment.js/2.17.1/moment.min.js"></script>

请在下面找到解决方案

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;

为此使用Moment.js

使用moment.js时,在JavaScript中使用以下代码

H, HH       24 hour time
h, or hh    12 hour time (use in conjunction with a or A)

format()方法以特定格式返回日期。

moment(new Date()).format("YYYY-MM-DD HH:mm"); // 24H clock
moment(new Date()).format("YYYY-MM-DD hh:mm A"); // 12H clock (AM/PM)
moment(new Date()).format("YYYY-MM-DD hh:mm a"); // 12H clock (am/pm)

dateObj.toLocaleString([locales[, options]])

选项1-使用语言环境

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));

注意:除Safari Atm之外,所有浏览器均支持

现代浏览器中,使用以下Intl.DateTimeFormat选项并强制使用12小时格式:

    let now = new Date();

    new Intl.DateTimeFormat('default',
        {
            hour12: true,
            hour: 'numeric',
            minute: 'numeric'
        }).format(now);

    // 6:30 AM

default如果您添加更多选项,则使用将遵循浏览器的默认语言环境,但仍将输出12小时格式。

英文的简短RegExp:

var d = new Date();
d = d.toLocaleTimeString().replace(/:\d+ /, ' '); // current time, e.g. "1:54 PM"

查看Datejs他们内置的格式化程序可以做到这一点:http : //code.google.com/p/datejs/wiki/APIDocumentation#toString

这是一个非常方便的库,尤其是如果您打算对日期对象进行其他操作。

我发现它在这里工作正常。

var date_format = '12'; /* FORMAT CAN BE 12 hour (12) OR 24 hour (24)*/


var d       = new Date();
var hour    = d.getHours();  /* Returns the hour (from 0-23) */
var minutes     = d.getMinutes();  /* Returns the minutes (from 0-59) */
var result  = hour;
var ext     = '';

if(date_format == '12'){
    if(hour > 12){
        ext = 'PM';
        hour = (hour - 12);

        if(hour < 10){
            result = "0" + hour;
        }else if(hour == 12){
            hour = "00";
            ext = 'AM';
        }
    }
    else if(hour < 12){
        result = ((hour < 10) ? "0" + hour : hour);
        ext = 'AM';
    }else if(hour == 12){
        ext = 'PM';
    }
}

if(minutes < 10){
    minutes = "0" + minutes; 
}

result = result + ":" + minutes + ' ' + ext; 

console.log(result);

和punker的例子在这里

<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>

这是另一种简单且非常有效的方法:

        var d = new Date();

        var weekday = new Array(7);
        weekday[0] = "Sunday";
        weekday[1] = "Monday";
        weekday[2] = "Tuesday";
        weekday[3] = "Wednesday";
        weekday[4] = "Thursday";
        weekday[5] = "Friday";
        weekday[6] = "Saturday";

        var month = new Array(11);
        month[0] = "January";
        month[1] = "February";
        month[2] = "March";
        month[3] = "April";
        month[4] = "May";
        month[5] = "June";
        month[6] = "July";
        month[7] = "August";
        month[8] = "September";
        month[9] = "October";
        month[10] = "November";
        month[11] = "December";

        var t = d.toLocaleTimeString().replace(/:\d+ /, ' ');

        document.write(weekday[d.getDay()] + ',' + " " + month[d.getMonth()] + " " + d.getDate() + ',' + " " + d.getFullYear() + '<br>' + d.toLocaleTimeString());

    </script></div><!-- #time -->

它将返回以下格式,例如

09:56 AM

如果小时数少于10,则还要在小时数的开头添加零

这是使用ES6语法的

const getTimeAMPMFormat = (date) => {
  let hours = date.getHours();
  let minutes = date.getMinutes();
  const ampm = hours >= 12 ? 'PM' : 'AM';
  hours = hours % 12;
  hours = hours ? hours : 12; // the hour '0' should be '12'
  hours = hours < 10 ? '0' + hours : hours;
  // appending zero in the start if hours less than 10
  minutes = minutes < 10 ? '0' + minutes : minutes;
  return hours + ':' + minutes + ' ' + ampm;
};
console.log(getTimeAMPMFormat(new Date)); // 09:59 AM

您可以使用此简单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';
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>
<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>
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;
}

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;
}

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>

一个简短而甜蜜的实现:

// returns date object in 12hr (AM/PM) format
var formatAMPM = function formatAMPM(d) {
    var h = d.getHours();
    return (h % 12 || 12)
        + ':' + d.getMinutes().toString().padStart(2, '0')
        + ' ' + (h < 12 ? 'A' : 'P') + 'M';
};

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";
本文地址:http://javascript.askforanswer.com/ruheyi12xiaoshiam-pmgeshixianshijavascriptriqishijian.html
文章标签: ,   ,   ,   ,  
版权声明:本文为原创文章,版权归 javascript 所有,欢迎分享本文,转载请保留出处!

文件下载

老薛主机终身7折优惠码boke112

上一篇:
下一篇:

评论已关闭!