你如何在JavaScript中以12小时制(AM/PM)显示日期和时间?
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} ${date.getHours() < 12 ? 'AM' : 'PM'}`
}
var today=new Date();
var noon=new Date(today.getFullYear(),today.getMonth(),today.getDate(),12,0,0);
var ampm = (today.getTime()<noon.getTime())?'am':'pm';
function formatTime( d = new Date(), ampm = true )
{
var hour = d.getHours();
if ( ampm )
{
var a = ( hour >= 12 ) ? 'PM' : 'AM';
hour = hour % 12;
hour = hour ? hour : 12; // the hour '0' should be '12'
}
var hour = checkDigit(hour);
var minute = checkDigit(d.getMinutes());
var second = checkDigit(d.getSeconds());
// https://dev59.com/XHM_5IYBdhLWcg3wXx5N
return ( ampm ) ? `${hour}:${minute}:${second} ${a}` : `${hour}:${minute}:${second}`;
}
function checkDigit(t)
{
return ( t < 10 ) ? `0${t}` : t;
}
document.querySelector("#time1").innerHTML = formatTime();
document.querySelector("#time2").innerHTML = formatTime( new Date(), false );
<p>ampm true: <span id="time1"></span> (default)</p>
<p>ampm false: <span id="time2"></span></p>
var date = new Date();
var hours = date.getHours();
var minutes = date.getMinutes();
var seconds = date.getSeconds();
var ampm = hours >= 12 ? "pm" : "am";
<h1 id="clock_display" class="text-center" style="font-size:40px; color:#ffffff">[CLOCK TIME DISPLAYS HERE]</h1>
<script>
var AM_or_PM = "AM";
function startTime(){
var today = new Date();
var h = today.getHours();
var m = today.getMinutes();
var s = today.getSeconds();
h = twelve_hour_time(h);
m = checkTime(m);
s = checkTime(s);
document.getElementById('clock_display').innerHTML =
h + ":" + m + ":" + s +" "+AM_or_PM;
var t = setTimeout(startTime, 1000);
}
function checkTime(i){
if(i < 10){
i = "0" + i;// add zero in front of numbers < 10
}
return i;
}
// CONVERT TO 12 HOUR TIME. SET AM OR PM
function twelve_hour_time(h){
if(h > 12){
h = h - 12;
AM_or_PM = " PM";
}
return h;
}
startTime();
</script>
{new Date(progress.position * 1000).toLocaleTimeString([], { hour: '2-digit', minute: '2-digit' }).substring(0,5)}
var d = new Date();
var hours = d.getHours() % 12;
hours = hours ? hours : 12;
var test = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][(d.getMonth() + 1)] + " " +
("00" + d.getDate()).slice(-2) + " " +
d.getFullYear() + " " +
("00" + hours).slice(-2) + ":" +
("00" + d.getMinutes()).slice(-2) + ":" +
("00" + d.getSeconds()).slice(-2) + ' ' + (d.getHours() >= 12 ? 'PM' : 'AM');
document.getElementById("demo").innerHTML = test;
<p id="demo" ></p>
const formatAMPM = (date) => {
try {
let time = date.split(" ");
let hours = time[4].split(":")[0];
let minutes = time[4].split(":")[1];
hours = hours || 12;
const ampm = hours >= 12 ? " PM" : " AM";
minutes = minutes < 10 ? `${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())
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;
}
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;
}
警告:toLocaleTimeString() 的行为可能因地区/位置而异。
量好再切。 - Abandoned Cart