Generate random date between two dates and times in Javascript

Question

I want to generate a random date between two dates and between two times in javascript. For instance I want to generate a random date (between 8 am and 6 pm) between today a

Answer 1

Since everyone is doing TypeScript now. Here's a more modern example with an example of how to use it.

const generateRandomDOB = (): string => {
    const random = getRandomDate(new Date('1950-02-12T01:57:45.271Z'), new Date('2001-02-12T01:57:45.271Z'))
    return random.toISOString();
}

function getRandomDate(from: Date, to: Date) {
    const fromTime = from.getTime();
    const toTime = to.getTime();
    return new Date(fromTime + Math.random() * (toTime - fromTime));
}

Answer 2

I think I understand what you are after. This will return a random date between start and end, with a random hour between startHour and endHour (which should be values in the range 0-23).

function randomDate(start, end, startHour, endHour) {
  var date = new Date(+start + Math.random() * (end - start));
  var hour = startHour + Math.random() * (endHour - startHour) | 0;
  date.setHours(hour);
  return date;
}

Answer 3

A single function.

    function (line) {
   return  new Date(new Date('2019-02-12T01:57:45.271Z').getTime() + Math.random() * (new Date('2020-02-12T01:57:45.271Z').getTime() - new Date('2019-02-12T01:57:45.271Z').getTime())).toISOString(); 
} 

Answer 4

Try this:

function getRandomDate(from, to) {
    from = from.getTime();
    to = to.getTime();
    return new Date(from + Math.random() * (to - from));
}

When creating a date you can set a time also:

var d = new Date(year, month, day, hours, minutes, seconds, milliseconds);

If you want the date to be, for example, between 8 am and 6 pm, simply set a random time after you get a random date.

So in this case the function would look like this:

function getRandomDate(fromDate, toDate, fromTime, toTime) {
    fromDate = fromDate.getTime();
    toDate = toDate.getTime();
    fromTime.setFullYear(1970,0,1); //reset the date
    toTime.setFullYear(1970,0,1); //because we only want a time here
    fromTime = fromTime.getTime();
    toTime = toTime.getTime();
    randomDate = new Date(fromDate + Math.random() * (toDate - fromDate));
    randomTime = new Date(fromTime + Math.random() * (toTime - fromTime));
    randomDate.setHours(randomTime.getHours());
    randomDate.setMinutes(randomTime.getMinutes());
    randomDate.setSeconds(randomTime.getSeconds());
}

Answer 5

You can use JS ability to convert a Date to an integer timestamp

Here is a simple working JSfiddle:

function randomTime(start, end) {
    var diff =  end.getTime() - start.getTime();
    var new_diff = diff * Math.random();
    var date = new Date(start.getTime() + new_diff);
    return date;
}

Answer 6

try this:

var yourRandomGenerator=function(rangeOfDays,startHour,hourRange){
    var today = new Date(Date.now());
    return new Date(today.getYear()+1900,today.getMonth(), today.getDate()+Math.random() *rangeOfDays, Math.random()*hourRange + startHour, Math.random()*60)
}

console.log(yourRandomGenerator(2,8,2));

here's a working fiddle.