How to get the day of week and the month of the year?

问题

I don\'t know much about Javascript, and the other questions I found are related to operations on dates, not only getting the information as I need it.

Objective

I wish to get the date as below-formatted:

Printed on Thursday, 27 January 2011 at 17:42:21

So far, I got the following:

var now = new Date();
var h = now.getHours();
var m = now.getMinutes();
var s = now.getSeconds();

h = checkTime(h);
m = checkTime(m);
s = checkTime(s);

var prnDt = \"Printed on Thursday, \" + now.getDate() + \" January \" + now.getFullYear() + \" at \" + h + \":\" + m + \":\" s;

I now need to know how to get the day of week and the month of year (their names).

Is there a simple way to make it, or shall I consider using arrays where I would simply index to the right value using now.getMonth() and now.getDay()?

回答1:

Yes, you'll need arrays.

var days = ['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday'];
var months = ['January','February','March','April','May','June','July','August','September','October','November','December'];

var day = days[ now.getDay() ];
var month = months[ now.getMonth() ];

Or you can use the date.js library.

EDIT:

If you're going to use these frequently, you may want to extend Date.prototype for accessibility.

(function() {
    var days = ['Sunday','Monday','Tuesday','Wednesday','Thursday','Friday','Saturday'];

    var months = ['January','February','March','April','May','June','July','August','September','October','November','December'];

    Date.prototype.getMonthName = function() {
        return months[ this.getMonth() ];
    };
    Date.prototype.getDayName = function() {
        return days[ this.getDay() ];
    };
})();

var now = new Date();

var day = now.getDayName();
var month = now.getMonthName();

回答2:

Use the standard javascript Date class. No need for arrays. No need for extra libraries.

See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString

var options = {  weekday: 'long', year: 'numeric', month: 'long', day: 'numeric', hour: '2-digit', minute: '2-digit', second: '2-digit', hour12: false };
var prnDt = 'Printed on ' + new Date().toLocaleTimeString('en-us', options);

console.log(prnDt);

回答3:

One thing you can also do is Extend date object to return Weekday by:

Date.prototype.getWeekDay = function() {
    var weekday = ["Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"];
    return weekday[this.getDay()];
}

so, you can only call date.getWeekDay();

回答4:

As @L-Ray has already suggested, you can look into moment.js as well

Sample

var today = moment();
var result = {
  day: today.format("dddd"),
  month: today.format("MMM")
}

document.write("<pre>" + JSON.stringify(result,0,4) + "</pre>");

<script src="https://cdnjs.cloudflare.com/ajax/libs/moment.js/2.13.0/moment.min.js"></script>

回答5:

Unfortunately, Date object in javascript returns information about months only in numeric format. The faster thing you can do is to create an array of months (they are not supposed to change frequently!) and create a function which returns the name based on the number.

Something like this:

function getMonthNameByMonthNumber(mm) { 
   var months = new Array("January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"); 

   return months[mm]; 
}

Your code therefore becomes:

var prnDt = "Printed on Thursday, " + now.getDate() + " " + getMonthNameByMonthNumber(now.getMonth) + " "+  now.getFullYear() + " at " + h + ":" + m + ":" s;

回答6:

var GetWeekDays = function (format) {
    var weekDays = {};

    var curDate = new Date();
    for (var i = 0; i < 7; ++i) {
        weekDays[curDate.getDay()] = curDate.toLocaleDateString('ru-RU', {
            weekday: format ? format : 'short'
        });

        curDate.setDate(curDate.getDate() + 1);
    }

    return weekDays;
};

me.GetMonthNames = function (format) {
    var monthNames = {};

    var curDate = new Date();
    for (var i = 0; i < 12; ++i) {
        monthNames[curDate.getMonth()] = curDate.toLocaleDateString('ru-RU', {
            month: format ? format : 'long'
        });

        curDate.setMonth(curDate.getMonth() + 1);
    }

    return monthNames;
};

回答7:

Using http://phrogz.net/JS/FormatDateTime_JS.txt you can just:

var now = new Date;
var prnDt = now.customFormat( "Printed on #DDDD#, #D# #MMMM# #YYYY# at #hhh#:#mm#:#ss#" );

回答8:

You can look at datejs which parses the localized date output for example.

The formatting may look like this, in your example:

new Date().toString('dddd, d MMMM yyyy at HH:mm:ss')

回答9:

That's simple. You can set option to display only week days in toLocaleDateString() to get the names. For example:

(new Date()).toLocaleDateString('en-US',{ weekday: 'long'}) will return only the day of the week. And (new Date()).toLocaleDateString('en-US',{ month: 'long'}) will return only the month of the year.

回答10:

From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toLocaleDateString

The toLocaleDateString() method returns a string with a language sensitive representation of the date portion of this date. The new locales and options arguments let applications specify the language whose formatting conventions should be used and allow to customize the behavior of the function. In older implementations, which ignore the locales and options arguments, the locale used and the form of the string returned are entirely implementation dependent.

Long form:

const options = { weekday: 'long' };
const date = new Date();
console.log(date.toLocaleDateString('en-US', options));

One liner:

console.log(new Date().toLocaleDateString('en-US', { weekday: 'long' }));

Note: there are other language options for locale, but the one presented here for for US English

回答11:

  function currentDate() {
      var monthNames = [ "JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE",
                     "JULY", "AUGUST", "SEPTEMBER", "OCTOBER", "NOVEMBER", "DECEMBER" ];
      var days = ['SUNDAY','MONDAY','TUESDAY','WEDNESDAY','THURSDAY','FRIDAY','SATURDAY'];                       
      var today = new Date();
      var dd   = today.getDate();
      var mm   = monthNames[today.getMonth()]; 
      var yyyy = today.getFullYear();
      var day  = days[today.getDay()];
      today = 'Date is :' + dd + '-' + mm + '-' + yyyy;
      document.write(today +"<br>");
      document.write('Day is : ' + day );
  }
  currentDate();

来源：https://stackoverflow.com/questions/4822852/how-to-get-the-day-of-week-and-the-month-of-the-year

标签

javascript

datetime

dayofweek