What is the significance of the strtotime() function and the division by 86400 in the provided PHP code snippet for highlighting rows based on specific dates?

The significance of the strtotime() function is that it converts a date string into a Unix timestamp, which is the number of seconds since the Unix Epoch (January 1, 1970). By dividing the timestamp by 86400, we convert it into the number of days since the Unix Epoch, which allows us to easily compare dates. This is useful for highlighting rows based on specific dates as it simplifies the date comparison process.

$current_date = strtotime(date("Y-m-d")); // Get the current date as a Unix timestamp
$target_date = strtotime("2022-12-25"); // Set the target date to highlight rows

if (($target_date - $current_date) / 86400 < 7) {
    // Highlight the row if the target date is less than 7 days away
    echo "<tr style='background-color: yellow;'>";
} else {
    echo "<tr>";
}