How does the mktime function in PHP calculate the number of seconds since the Unix Epoch?

The mktime function in PHP calculates the number of seconds since the Unix Epoch by taking the parameters for the hour, minute, second, month, day, and year, and converting them into a Unix timestamp. This timestamp represents the number of seconds that have elapsed since January 1, 1970. To calculate the number of seconds since the Unix Epoch using mktime, simply provide the necessary parameters to the function and it will return the corresponding Unix timestamp.

$timestamp = mktime(0, 0, 0, 1, 1, 1970);
echo $timestamp;