javascript - Day Name from Date in JS

Question

I need to display the name of the day given a date (like "05/23/2014") which I get from a 3rd party.

I've tried using Date, but I only get the date.

What is the correct way to get the name of the day?

Answer 1

Ahum, three years later...

Why nobody uses the methods provided by the standard javascript Date class (except Callum Linington)?

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

Getting the day name from a date:

function getDayName(dateStr, locale)
{
    var date = new Date(dateStr);
    return date.toLocaleDateString(locale, { weekday: 'long' });        
}

var dateStr = '05/23/2014';
var day = getDayName(dateStr, "nl-NL"); // Gives back 'Vrijdag' which is Dutch for Friday.

Getting all weekdays in an array:

function getWeekDays(locale)
{
    var baseDate = new Date(Date.UTC(2017, 0, 2)); // just a Monday
    var weekDays = [];
    for(i = 0; i < 7; i++)
    {       
        weekDays.push(baseDate.toLocaleDateString(locale, { weekday: 'long' }));
        baseDate.setDate(baseDate.getDate() + 1);       
    }
    return weekDays;
}

var weekDays = getWeekDays('nl-NL'); // Gives back { 'maandag', 'dinsdag', 'woensdag', 'donderdag', 'vrijdag', 'zaterdag', 'zondag'} which are the days of the week in Dutch.

For American dates use 'en-US' as locale.