Elegant method to generate array of random dates within two dates

问题

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
}

回答1:

Maybe I am missing something, but isn't this it?

function randomDate(start, end) {
    return new Date(start.getTime() + Math.random() * (end.getTime() - start.getTime()));
}

randomDate(new Date(2012, 0, 1), new Date())

回答2:

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

回答3:

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.

回答4:

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().

来源：https://stackoverflow.com/questions/9035627/elegant-method-to-generate-array-of-random-dates-within-two-dates

标签

javascript

date

random

jquery-ui-datepicker