What is the issue with converting a date to a number in PHP?

Converting a date to a number in PHP can lead to unexpected results or errors because dates are typically stored as strings or objects, not numbers. To solve this issue, you can use the strtotime() function in PHP to convert a date string to a Unix timestamp, which is a numeric representation of the date and time.

$date = "2022-01-01";
$timestamp = strtotime($date);
echo $timestamp;