What is the function in PHP that can be used to convert a date string into a timestamp?

To convert a date string into a timestamp in PHP, you can use the strtotime() function. This function takes a date string as input and returns a Unix timestamp representing that date and time. The strtotime() function is versatile and can handle various date formats, making it a convenient way to convert date strings into timestamps in PHP.

$dateString = "2022-01-01";
$timestamp = strtotime($dateString);

echo $timestamp;