How to Compare two date in JavaScript

In this JavaScript tutorial, We will learn the comparison of two dates using javascript, this is a very common problem in web development. I am using Date() class to convert date and store into the variable, finally comparing those dates and alert messages.

Two dates can be compared by converting them to numeric values that correspond to their times. To begin, we’ll use the getTime() function to convert the Date to a numerical value.

Method to Compare two date in JavaScript

Let’s create some examples to compare two dates.

Example 1: Compare two Dates Using JavaScript and jQuery

We are using jquery to get input values from the text input and then comparing using getTime().

function validate() {  
 var startDate = new Date(jQuery('#from').val().replace(/-/g, '/')).getTime();  
 var endDate =  new Date(jQuery('#to').val().replace(/-/g, '/')).getTime();   
 var date = new Date();  
 var currentDate = new Date(date.getMonth() + 1 + '/' + date.getDate() + '/' + date.getFullYear()).getTime();  
 if (startDate > endDate){  
  alert('From date is greater than To date');  
  return false;  
 } else if (startDate > currentDate || endDate > currentDate) {  
  alert('You have entered future date');  
 } else {  
  return true;  
 }  
}  

Example 2: Compare two dates Using Javascript

We are using pure js method to compare two dates.

<script>
 // Current Date
 var g1 = new Date();
 var g2 = new Date();
 if (g1.getTime() === g2.getTime())
  document.write("Both dates are equal");
 else
  document.write("Not equal");
 javascript: ;
</script>

Example 3: Compare dates Using MomentJS

The MomentJS provides the following methods to compare dates with or without a timestamp.

• isSame: Checks two-moment date objects are equal or not.
• isBefore: One date is before another date
• isAfter: one date is after another date

Sample Example:

moment('2022-01-22').isSame('2022-01-12'); // false
moment('2022-01-22').isBefore('2022-01-12'); // false
moment('2022-01-22').isAfter('2022-01-12'); // true