To check if a date is a past date in PHP, you can compare the given date with the current date using the DateTime class. Here’s a step-by-step guide on how to achieve this:

Step 1: Get the date to be checked. This can be from user input, a database, or any other data source.

$date_to_check = '2023-05-25'; // Replace this with the date to be checked

Step 2: Create a DateTime object for the date to be checked.

$check_date = new DateTime($date_to_check);

Step 3: Get the current date as a DateTime object.

$current_date = new DateTime();

Step 4: Compare the two dates to check if the given date is in the past.

if ($check_date < $current_date) {
    echo "The date is a past date.";
} else {
    echo "The date is not a past date.";
}

Here’s the complete code in one block:

<?php
$date_to_check = '2023-05-25'; // Replace this with the date to be checked
$check_date = new DateTime($date_to_check);
$current_date = new DateTime();

if ($check_date < $current_date) {
    echo "The date is a past date.";
} else {
    echo "The date is not a past date.";
}
?>

For example, if the $date_to_check is set to '2023-05-25' and the current date is '2023-05-24', the output will be:

The date is a past date.

If the $date_to_check is set to '2023-05-26' and the current date is '2023-05-24', the output will be:

The date is not a past date.

In this example, we use the DateTime class to handle dates and compare the given date ($check_date) with the current date ($current_date) using the less-than (<) operator. If the given date is less than the current date, it is considered a past date. Otherwise, it is not a past date.