. getmonth()返回一个从零开始的数字，所以为了得到正确的月份，你需要加1，所以在五月调用. getmonth()将返回4而不是5。

因此，在代码中，我们可以使用currentdate.getMonth()+1来输出正确的值。此外:

.getDate()返回月份的日期<-这是你想要的 .getDay()是Date对象的一个单独方法，它将返回一个整数，表示一周中的当前日期(0-6)0 ==星期日等

所以你的代码应该是这样的:

var currentdate = new Date(); 
var datetime = "Last Sync: " + currentdate.getDate() + "/"
                + (currentdate.getMonth()+1)  + "/" 
                + currentdate.getFullYear() + " @ "  
                + currentdate.getHours() + ":"  
                + currentdate.getMinutes() + ":" 
                + currentdate.getSeconds();

JavaScript Date实例继承自Date.prototype。您可以修改构造函数的原型对象，以影响JavaScript Date实例继承的属性和方法

您可以使用Date原型对象创建一个新方法，该方法将返回今天的日期和时间。这些新方法或属性将由Date对象的所有实例继承，因此在需要重用此功能时特别有用。

// For todays date;
Date.prototype.today = function () { 
    return ((this.getDate() < 10)?"0":"") + this.getDate() +"/"+(((this.getMonth()+1) < 10)?"0":"") + (this.getMonth()+1) +"/"+ this.getFullYear();
}

// For the time now
Date.prototype.timeNow = function () {
     return ((this.getHours() < 10)?"0":"") + this.getHours() +":"+ ((this.getMinutes() < 10)?"0":"") + this.getMinutes() +":"+ ((this.getSeconds() < 10)?"0":"") + this.getSeconds();
}

然后，您可以通过执行以下操作简单地检索日期和时间:

var newDate = new Date();
var datetime = "LastSync: " + newDate.today() + " @ " + newDate.timeNow();

或者将该方法调用为内联，这样它就是-

var datetime = "LastSync: " + new Date().today() + " @ " + new Date().timeNow();

这应该可以达到目的:

function dateToString(date) {
    var month = date.getMonth() + 1;
    var day = date.getDate();
    var dateOfString = (("" + day).length < 2 ? "0" : "") + day + "/";
    dateOfString += (("" + month).length < 2 ? "0" : "") + month + "/";
    dateOfString += date.getFullYear();
    return dateOfString;
}

var currentdate = new Date();
var datetime = "Last Sync: ";
datetime += dateToString(currentdate );
datetime += + currentdate.getHours() + ":"
            + currentdate.getMinutes() + ":"
            + currentdate.getSeconds();

如果有人在寻找功能

console.log(formatAMPM());
function formatAMPM() {
  var date = new Date();
  var hours = date.getHours();
  var minutes = date.getMinutes();
  var seconds = date.getSeconds();
  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;
  return strTime = date.getMonth() + '/' + date.getDay()+'/'+date.getFullYear()+' '+ hours + ':' + minutes +':'+ seconds + " " +ampm;
}

这是英国时区的例子。为特定时区设置偏移量。 例如:印度:+05:30，英国:+1

 function realUKTime() {
        // create Date object for current location
        var d = new Date();
        offset ='+1';
       
        // convert to msec
        // subtract local time zone offset
        // get UTC time in msec
        var utc = d.getTime() + (d.getTimezoneOffset() * 60000);

        // create new Date object for different city
        // using supplied offset
        var nd = new Date(utc + (3600000*offset));

        // return time as a string
        var s = nd.getSeconds();
        var i = nd.getMinutes();
        var h = nd.getHours();
        var cDate =  nd.getDate();
        var m =  nd.getUTCMonth();
        var y = nd.getFullYear();

       var newUkTime = nd.toDateString() + " "+ (Number(h)-1)+":"+i+':'+s
        $("#realTime").html(newUkTime);

    }

    setInterval(realUKTime(),1000);

输出::Mon 12月27日2021 12:6:3

获取当前日期和时间

var now = new Date(); 
  var datetime = now.getFullYear()+'/'+(now.getMonth()+1)+'/'+now.getDate(); 
  datetime += ' '+now.getHours()+':'+now.getMinutes()+':'+now.getSeconds(); 

我善意的回答是使用这个小小的JS: https://github.com/rhroyston/clock-js

clock.now   --> 1462248501241
clock.time  --> 11:08 PM
clock.weekday   --> monday
clock.day   --> 2
clock.month --> may
clock.year  --> 2016
clock.since(1462245888784)  --> 44 minutes
clock.until(1462255888784)  --> 2 hours
clock.what.time(1462245888784)  --> 10:24 PM
clock.what.weekday(1461968554458)   --> friday
clock.what.day('14622458887 84')    --> 2
clock.what.month(1461968554458) --> april
clock.what.year('1461968554458')    --> 2016
clock.what.time()   --> 11:11 PM
clock.what.weekday('14619685abcd')  -->     clock.js error : expected unix timestamp as argument
clock.unit.seconds  --> 1000
clock.unit.minutes  --> 60000
clock.unit.hours    --> 3600000
clock.unit.days --> 86400000
clock.unit.weeks    --> 604800000
clock.unit.months   --> 2628002880
clock.unit.years    --> 31536000000