How can PHP developers efficiently compare dates and times, such as calculating the difference between registration dates and current dates for user notifications?

When comparing dates and times in PHP, developers can use the DateTime class to easily calculate the difference between two dates. By creating DateTime objects for the registration date and current date, developers can then use the diff() method to get the interval between the two dates in a format that can be easily manipulated for user notifications.

// Example code to calculate the difference between registration date and current date
$registrationDate = new DateTime('2022-01-15');
$currentDate = new DateTime();
$interval = $currentDate->diff($registrationDate);

echo $interval->format('%R%a days');