JAVASCRIPT

How do I get the number of days between two dates in JavaScript

let today = new Date().toISOString().slice(0, 10)

const startDate  = '2021-04-15';
const endDate    = today;

const diffInMs   = new Date(endDate) - new Date(startDate)
const diffInDays = diffInMs / (1000 * 60 * 60 * 24);


alert( diffInDays  );

javascript difference between two dates in days

const diffDays = (date, otherDate) => Math.ceil(Math.abs(date - otherDate) / (1000 * 60 * 60 * 24));

// Example
diffDays(new Date('2014-12-19'), new Date('2020-01-01'));   // 1839

get all date between two dates in javascript

// Returns an array of dates between the two dates
function getDates (startDate, endDate) {
  const dates = []
  let currentDate = startDate
  const addDays = function (days) {
    const date = new Date(this.valueOf())
    date.setDate(date.getDate() + days)
    return date
  }
  while (currentDate <= endDate) {
    dates.push(currentDate)
    currentDate = addDays.call(currentDate, 1)
  }
  return dates
}

// Usage
const dates = getDates(new Date(2013, 10, 22), new Date(2013, 11, 25))
dates.forEach(function (date) {
  console.log(date)
})

calculate days between two dates in javascript

<input id="first" value="25/2/2021"/>
<input id="second" value="26/2/2021"/>