Trying something like this but I know I've newb'd it all up:
if($user_data->last_access ("0000-00-00 00:00:00") > 60*60*24) {die($base_error);}
The field "last_access" is in the "datetime" format and is updated to the current date any time someone logs into that record.
I'd like to error out my script if the time is greater than "0000-00-00 00:00:00" in that record.
This worked for me, so I'm going with it.
if($user_data->last_access > 0) {die($base_error);}