'Elegant method to generate array of random dates within two dates

I have a datepicker where I show two months and I want to randomly choose 3 dates in each visible month 

  $('.date').datepicker({
    minDate: new Date(),
    dateFormat: 'DD, MM, d, yy',
    constrainInput: true,
    beforeShowDay: processDates,
    numberOfMonths: 2,
    showButtonPanel: true,
    showOn: "button",
    buttonImage: "images/calendar_icon.jpg",
    buttonImageOnly: true    
  });

Here is my calculation

var now = new Date();
var nowTime = parseInt(now.getTime()/1000);
var randomDateSet = {};

function getRandomSet(y,m) {
  var monthIndex = "m"+y+""+m; // m20121 for Jan
  if (randomDateSet[monthIndex]) return randomDateSet[monthIndex];
  // generate here
.
. - I need this part
.
  return randomDateSet[monthIndex];
}

function processDay(date) { // this is calculated for each day so we need a singleton for the array
  var dateTime = parseInt(date.getTime()/1000);
  if (dateTime <= (nowTime-86400)) {
    return [false]; // earlier than today
  }
  var m = date.getMonth(), d = date.getDate(), y = date.getFullYear();
  var randomDates = getRandomSet(y,m);

  for (i = 0; i < randomDates.length; i++) {
    if($.inArray((m+1) + '-' + d + '-' + y,randomDates) != -1 || new Date() > date) {
      return [true,"highlight","Some message"];
    }
  }
  return [true,"normal"]; // ordinary day
}
javascriptdaterandomjquery-ui-datepicker


Solution 1:[1]

new Date(+(new Date()) - Math.floor(Math.random()*10000000000))

Solution 2:[2]

Using Moment.js && @Demven Weir's answer to get a string value like "03/02/1975".

moment(new Date(+(new Date()) - Math.floor(Math.random()*10000000000)))
.format('MM/DD/YYYY');

NOTE: Keep adding a zero at a time to increase the span of years produced.

Solution 3:[3]

You can convert the boundary dates to integers (Date.getTime()) and then use Math.random() to generate your random dates within given boundaries. Then go back to Date objects with Date.setTime().

Solution 4:[4]

function generateRandomDate() {
return new Date(+(new Date()) - Math.floor(Math.random() * 10000000000));
}

(new generateRandomDate()).toLocaleDateString('en-US')

You will get a random date in US format 4/25/2021

See this Demo on jsfiddle

Solution 5:[5]

You can use this snippet to get random date and format;

const emptyDate = new Date();
const randomDate = new Date();
const dateFormatter = Intl.DateTimeFormat('sv-SE');
const formattedRandomDate = dateFormatter.format(emptyDate.setDate(randomDate.getDate() - Math.floor(Math.random()*1000)));

Solution 6:[6]

From examples in date-fns

const result = eachDayOfInterval({
  start: new Date(2014, 9, 6),
  end: new Date(2014, 9, 10)
})

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1 Petter Friberg
Solution 2 SoEzPz
Solution 3 bububaba
Solution 4 Husam Ebish
Solution 5 Mahir Uslu
Solution 6 Kai - Kazuya Ito

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