Javascript 格式日期/时间

我需要改变日期/时间从 2014-08-2015:30:00看起来像 2014年8月20日下午3:30

这可以通过使用 javascript 的 Date 对象来实现吗?

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For the date part:(month is 0-indexed while days are 1-indexed)

var date = new Date('2014-8-20');
console.log((date.getMonth()+1) + '/' + date.getDate() + '/' +  date.getFullYear());

for the time you'll want to create a function to test different situations and convert.

Yes, you can use the native javascript Date() object and its methods.

For instance you can create a function like:

function formatDate(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 (date.getMonth()+1) + "/" + date.getDate() + "/" + date.getFullYear() + "  " + strTime;
}


var d = new Date();
var e = formatDate(d);


alert(e);

And display also the am / pm and the correct time.

Remember to use getFullYear() method and not getYear() because it has been deprecated.

DEMO http://jsfiddle.net/a_incarnati/kqo10jLb/4/

You can do that:

function formatAMPM(date) { // This is to display 12 hour format like you asked
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;
}


var myDate = new Date();
var displayDate = myDate.getMonth()+ '/' +myDate.getDate()+ '/' +myDate.getFullYear()+ ' ' +formatAMPM(myDate);
console.log(displayDate);

Fiddle

I don't think that can be done RELIABLY with built in methods on the native Date object. The toLocaleString method gets close, but if I am remembering correctly, it won't work correctly in IE < 10. If you are able to use a library for this task, MomentJS is a really amazing library; and it makes working with dates and times easy. Otherwise, I think you will have to write a basic function to give you the format that you are after.

function formatDate(date) {
var year = date.getFullYear(),
month = date.getMonth() + 1, // months are zero indexed
day = date.getDate(),
hour = date.getHours(),
minute = date.getMinutes(),
second = date.getSeconds(),
hourFormatted = hour % 12 || 12, // hour returned in 24 hour format
minuteFormatted = minute < 10 ? "0" + minute : minute,
morning = hour < 12 ? "am" : "pm";


return month + "/" + day + "/" + year + " " + hourFormatted + ":" +
minuteFormatted + morning;
}

Please do not reinvent the wheel. There are many open-source and COTS solutions that already exist to solve this problem.

Please take a look at the following JavaScript libraries:


Demo

Update: I wrote a one-liner using Moment.js Luxon below.

const { DateTime } = luxon;


const value = DateTime
.fromFormat("2014-08-20 15:30:00", "yyyy-MM-dd HH:mm:ss")
.toFormat('MM/dd/yyyy h:mm a');


console.log(value); // 08/20/2014 3:30 PM
<script src="https://cdnjs.cloudflare.com/ajax/libs/luxon/1.26.0/luxon.min.js"></script>

Here is the original version using Moment. Since Luxon is the successor to Moment, I have included this as an alternative.

const value = moment('2014-08-20 15:30:00').format('MM/DD/YYYY h:mm a');


console.log(value); // 08/20/2014 3:30 pm
<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.29.1/moment.min.js"></script>