如何以12小时格式(AM/PM)显示JavaScript datetime对象?
当前回答
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 >
其他回答
<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>
en-US的短RegExp:
var d = new Date();
d = d.toLocaleTimeString().replace(/:\d+ /, ' '); // current time, e.g. "1:54 PM"
希望这个答案比其他答案更容易理解(尤其是对新手来说)。
以下是我在一些站点中实现的解决方案,用于通知上次修改站点代码的时间。它通过date的选项参数实现AM/PM时间。toLocaleDateString(参见相关的Mozilla文档)。
// Last time page code was updated/changed
const options = {
year: "numeric",
month: "long",
weekday: "long",
day: "numeric",
hour: "numeric",
minute: "numeric",
second: "numeric",
hour12: true // This is the line of code we care about here
/*
false: displays 24hs format for time
true: displays 12, AM and PM format
*/
};
let last = document.lastModified;
let date = new Date(last);
let local = date.toLocaleDateString("en-US", options);
let fullDate = `${local}`;
document.getElementById("updated").textContent = fullDate;
输出的格式是:
Saturday, May 28, 2022, 8:38:50 PM
该输出然后显示在以下HTML代码中:
<p>Last update: <span id="updated">_update_date_goes_here</span></p>
注意:在这个用例中,是文档。lastModified有一些奇怪的行为,这取决于它是在本地运行还是在外部服务器上运行(参见这个堆栈溢出问题)。虽然当我在我的GitHub页面上运行它时,它可以正常工作(你应该在网站的页脚处看到它在运行)。
它将返回如下格式
09:56 AM
如果小时数小于10,则在start中添加0
这里使用的是ES6语法
const getTimeAMPMFormat = (date) => { let hours = date. gehours (); let minutes = date.getMinutes(); Const 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' 小时=小时< 10 ?'0' + hours:小时; //如果hours小于10,则在开始时添加0 分钟=分钟< 10 ?'0' + minutes: minutes; 返回小时+ ':' +分钟+ ' ' + ampm; }; console.log (getTimeAMPMFormat(新日期));// 09:59 am
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;
}