Generating random dates between start date and end date in utc format using javascript

Question

How can i generate random dates between two dates in utc format using javascript? example: start date is 23-01-25 02:07:04 and end date is 23-02-25 02:07:04 I want a list of random dates between start date & end date as below: [23-01-26 02:07:04,23-02-02 02:07:04,.....]

This is my Javasxript code:

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

const d = randomDate(new Date(2023, 04, 01), new Date(2023, 04, 12));
console.log(d);

But it gives wrong output:

2023-05-08T17:09:26.445Z

Can anyone suggest me a proper way to get solution

Answer 1

As others have mentioned, months in JavaScript are indexed from 0-11.

See: Date.prototype.setMonth()

monthValue
An integer representing the month: 0 for January, 1 for February, and so on.

const
  startDate = new Date(2023, 4, 1), // 2023-05-01
  endDate = new Date(2023, 4, 12);  // 2023-05-12

// Generate 1 million random dates between the provided range...
for (let i = 0; i < 1_000_000; i++) {
  const randomDate = getRandomDate(startDate, endDate);
  if (randomDate < startDate || startDate > endDate) {
    throw new Error(`Date out of range: ${randomDate}`);
  }
}

// Should get here if there are no range errors...
console.log('No errors...');

function getRandomDate(startDate, endDate) {
  if (arguments.length === 1) {
    endDate = new Date(startDate.getTime());
    startDate = new Date();
  }
  return new Date(getRandomInt(startDate.getTime(), endDate.getTime()));
}

function getRandomInt(min, max) {
  if (arguments.length === 1) {
    max = min;
    min = 0;
  }
  return Math.floor(Math.random() * (max - min + 1)) + min;
}