如何以12小时格式(AM/PM)显示JavaScript datetime对象?
当前回答
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";
其他回答
<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>
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)。
您可以使用这段简单的代码来确定am或PM
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';
在现代浏览器中,使用Intl。DateTimeFormat和强制12小时格式选项:
let now = new Date();
new Intl.DateTimeFormat('default',
{
hour12: true,
hour: 'numeric',
minute: 'numeric'
}).format(now);
// 6:30 AM
如果您添加更多选项,使用default将尊重浏览器的默认区域,但仍将输出12小时格式。
我发现它在这里工作得很好。
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);
result = hour;
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);
这是活塞的例子