First Issue:
You can use:
list($month,$day,$year)=preg_split("/[,\s]/",$date); // (untested!)
or you can use the strtotime() function, which will convert it to a php datetime, and then do whatever you need to (maybe using date() to reformat or whatever)
Second Issue:
MySQL has a datetime format, which is probably the best to use. Then, if you use MySQL's UNIX_TIMESTAMP function when selecting rows, it'll automatically be in PHP's format...
For more information, there are tons of tutorials on the net, such as this one (not that I've used it, but a quick search yielded this) http://www.devshed.com/c/a/MySQL/Practical-Date-Time-examples-with-PHP-and-MySQL/