JS to generate a random date between two date variables

Hello Again,
Trying to automate a task for a colleague and one of the requirements is giving me a hard time, I don’t have a background in JS so it isnt my strong suite. I have two dates which I am pulling from an input csv file, “start” and “end.” I need to use these two dates and generate a random date between the two, then save that date to a new variable called DOB. I have been looking around here and on other JS pages but cant seem to get anything to work - closest I get is code that works but “DOB” returns as “Undefined”

Thanks for any help!

I have a “Difference between two dates” script here. Maybe that helps as starting point:

const date1 = new Date('7/13/2010');
const date2 = new Date('12/15/2010');
const diffTime = Math.abs(date2.getTime() - date1.getTime());
const diffDays = Math.ceil(diffTime / (1000 * 60 * 60 * 24)); 
console.log(diffDays);

In action: http://jsfiddle.net/JS69L/1/