What potential issues may arise when deleting advertisements based on their display duration in PHP?

Potential issue: One potential issue that may arise when deleting advertisements based on their display duration in PHP is that the logic for determining when to delete the advertisements may not be accurately implemented. This could result in advertisements being deleted too early or not being deleted at all, leading to incorrect display of ads on the website. To solve this issue, it is important to carefully calculate the display duration of each advertisement and ensure that the deletion logic is correctly implemented to remove ads that have exceeded their display duration.

// Example code to delete advertisements based on their display duration
$current_time = time();

// Assuming $advertisements is an array of advertisements with 'display_duration' and 'start_time' properties
foreach ($advertisements as $key => $ad) {
    $end_time = $ad['start_time'] + $ad['display_duration'];
    
    if ($current_time >= $end_time) {
        unset($advertisements[$key]);
    }
}

// Update the advertisements array or database with the deleted advertisements