How to calculate the difference between two dates in PHP ?

In this article, we will see how to calculate the difference between 2 dates in PHP, along with understanding its implementation through the examples. Given two dates ie., start_date and end_date & we need to find the difference between the two dates.

Consider the below example:

Input: start_date: 2016-06-01 22:45:00 
       end_date: 2018-09-21 10:44:01
Output: 2 years, 3 months, 21 days, 11 hours, 59 minutes, 1 seconds
Explanation: The difference of 2 dates will give the date in complete format.

Method 1: Using date_diff() Function

This function is used to find the difference between two dates. This function will return a DateInterval object on the success and returns FALSE on failure.

Example: This example illustrates the use of the date_diff() function to calculate the difference between the 2 dates.

PHP

<?php

  // Creates DateTime objects
  $datetime1 = date_create('2016-06-01');
  $datetime2 = date_create('2018-09-21');

  // Calculates the difference between DateTime objects
  $interval = date_diff($datetime1, $datetime2);

  // Printing result in years & months format
  echo $interval->format('%R%y years %m months');
?>

Output:

+2 years 3 months

Method 2: To use the date-time mathematical formula to find the difference between two dates. It returns the years, months, days, hours, minutes, seconds between two specified dates.

Example: In this example, we will be using the date-time mathematical formula to calculate the difference between the dates that will be returned in years, months, days, hours, minutes, seconds.

PHP

<?php

  // Declare and define two dates
  $date1 = strtotime("2016-06-01 22:45:00");
  $date2 = strtotime("2018-09-21 10:44:01");

  // Formulate the Difference between two dates
  $diff = abs($date2 - $date1);

  // To get the year divide the resultant date into
  // total seconds in a year (365*60*60*24)
  $years = floor($diff / (365*60*60*24));

  // To get the month, subtract it with years and
  // divide the resultant date into
  // total seconds in a month (30*60*60*24)
  $months = floor(($diff - $years * 365*60*60*24)
                                 / (30*60*60*24));

  // To get the day, subtract it with years and
  // months and divide the resultant date into
  // total seconds in a days (60*60*24)
  $days = floor(($diff - $years * 365*60*60*24 -
               $months*30*60*60*24)/ (60*60*24));

  // To get the hour, subtract it with years,
  // months & seconds and divide the resultant
  // date into total seconds in a hours (60*60)
  $hours = floor(($diff - $years * 365*60*60*24
         - $months*30*60*60*24 - $days*60*60*24)
                                     / (60*60));

  // To get the minutes, subtract it with years,
  // months, seconds and hours and divide the
  // resultant date into total seconds i.e. 60
  $minutes = floor(($diff - $years * 365*60*60*24
           - $months*30*60*60*24 - $days*60*60*24
                            - $hours*60*60)/ 60);

  // To get the minutes, subtract it with years,
  // months, seconds, hours and minutes
  $seconds = floor(($diff - $years * 365*60*60*24
           - $months*30*60*60*24 - $days*60*60*24
                  - $hours*60*60 - $minutes*60));

  // Print the result
  printf("%d years, %d months, %d days, %d hours, "
       . "%d minutes, %d seconds", $years, $months,
               $days, $hours, $minutes, $seconds);
?>

Output:

2 years, 3 months, 21 days, 11 hours, 59 minutes, 1 seconds

Method 3: This method is used to get the total number of days between two specified dates.

PHP

<?php

  // Declare two dates
  $start_date = strtotime("2018-06-08");
  $end_date = strtotime("2018-09-19");

  // Get the difference and divide into
  // total no. seconds 60/60/24 to get
  // number of days
  echo "Difference between two dates: "
      . ($end_date - $start_date)/60/60/24;
?>

Output:

Difference between two dates: 103

PHP is a server-side scripting language designed specifically for web development. You can learn PHP from the ground up by following this PHP Tutorial and PHP Examples.