TimeBetweenDates.js

function timeBetweenDates (dateTo, dateFrom) {
  // get total seconds between the times
  let delta = Math.abs(date_future - date_now) / 1000
  // calculate (and subtract) whole days
  let days = Math.floor(delta / 86400)
  delta -= days * 86400
  // calculate (and subtract) whole hours
  let hours = Math.floor(delta / 3600) % 24
  delta -= hours * 3600
  // calculate (and subtract) whole minutes
  let minutes = Math.floor(delta / 60) % 60
  delta -= minutes * 60
  // what's left is seconds
  let seconds = delta % 60
  
  return {
    days: days,
    hours: hours,
    minutes: minutes,
    seconds: seconds
  }
}