Difference between two dates

Write a function that takes two valid dates as an input and returns the difference between them in the number of days.

Example

Input:
'10/15/2020' // mm/dd/yyyy
'12/1/2020'  // mm/dd/yyyy

Output:
47

The good thing about working with JavaScript dates is that we can simply subtract two dates and will get the time difference in milliseconds.

We can then convert this millisecond to get the number of days, weeks, months.

In a day we have around 86400000 milliseconds.

const DAY_IN_MILLISECONDS = 1000 * 60 * 60 * 24;
//1000 * seconds * minutes * hours

Thus we can divide the difference by this number and we will get our number of days.

const getDaysBetweenDates = (dateText1, dateText2) => {
    //millseconds in a day
    const DAY_IN_MILLISECONDS = 1000 * 60 * 60 * 24;
  
    //convert the date strings to actual dates
    const date1 = new Date(dateText1);
    const date2 = new Date(dateText2);
  
    // get the difference between the two days
    const diffTime = Math.abs(date2 - date1);
  
    // divide it by no of milliseconds in a single day
    const diffDays = Math.ceil(diffTime / DAY_IN_MILLISECONDS);
  
    //return the days
    return diffDays;
}

Input:
//1. mm/dd/yyyy 2.mm/dd/yyyy
console.log(getDaysBetweenDates('10/15/2020', '12/1/2020'));

//1. yyyy-mm-dd 2.mm/dd/yyyy
console.log(getDaysBetweenDates('2022-01-30', '12/1/2020'));

Output:
47
426