What potential pitfalls should be considered when using date functions in PHP to change images at specific times?

When using date functions in PHP to change images at specific times, it's important to consider timezones to ensure the images change at the intended time regardless of the server's timezone. Additionally, make sure to handle any potential caching issues that may prevent the updated images from displaying immediately. Lastly, consider the performance impact of frequently checking the current time to determine when to switch images.

// Set the timezone to ensure accurate time calculations
date_default_timezone_set('Your/Timezone');

// Check the current time and display the appropriate image
$current_time = date('H:i');
if ($current_time >= '08:00' && $current_time <= '17:00') {
    echo '<img src="daytime_image.jpg" alt="Daytime Image">';
} else {
    echo '<img src="nighttime_image.jpg" alt="Nighttime Image">';
}