JavaScript: Get time differences in months between two dates

JavaScript Datetime: Exercise-48 with Solution

Time Diff in Months

Write a JavaScript function to get time differences in months between two dates.

Test Data:
dt1 = new Date("June 13, 2014 08:11:00");
dt2 = new Date("October 19, 2014 11:13:00");
console.log(diff_months(dt1, dt2));
5

Sample Solution:

JavaScript Code:

// Define a function called diff_months that calculates the difference in months between two given dates (dt2 and dt1).
function diff_months(dt2, dt1) 
 {
  // Calculate the difference in milliseconds between the two dates.
  var diff =(dt2.getTime() - dt1.getTime()) / 1000;
  // Convert the difference from milliseconds to months by dividing it by the number of milliseconds in an hour, a day, a week, and approximately 4 weeks in a month.
  diff /= (60 * 60 * 24 * 7 * 4);
  // Round the result to the nearest integer using Math.round().
  return Math.abs(Math.round(diff));
  
 }

// Define two Date objects representing different dates.
dt1 = new Date(2014,10,2);
dt2 = new Date(2014,10,11);
// Calculate and log the difference in months between the two dates using the diff_months function.
console.log(diff_months(dt1, dt2));

// Define two Date objects representing different dates.
dt1 = new Date("June 13, 2014 08:11:00");
dt2 = new Date("October 19, 2014 11:13:00");
// Calculate and log the difference in months between the two dates using the diff_months function.
console.log(diff_months(dt1, dt2));

Output:

0
5

Explanation:

In the exercise above,

• The "diff_months()" function takes two Date objects, 'dt2' and 'dt1', as parameters.
• Inside the function, it calculates the difference in milliseconds between the two dates using the "getTime()" method.
• It then converts the difference from milliseconds to months by dividing it successively by the number of milliseconds in an hour, a day, a week, and approximately 4 weeks in a month.
• The result is rounded to the nearest integer using "Math.round()" to get the whole number of months.
• Finally, the absolute value of the rounded difference is returned.

Flowchart:

Live Demo:

For more Practice: Solve these Related Problems:

• Write a JavaScript function that calculates the difference in months between two dates by comparing year and month values.
• Write a JavaScript function that adjusts for the day differences when computing the month difference.
• Write a JavaScript function that returns the month difference as an integer, rounding down partial months.
• Write a JavaScript function that validates the input dates and computes the total months difference combining year and month parts.

Go to:

• JavaScript Date Exercises Home ↩
• JavaScript Exercises Home ↩

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