I can't find the answer to this readily in a post merger thread.

it used to be common to book round trips with "open" return dates. I haven't had a need to do this before, but with a son returning home from college with a known coming home date but only a "sometime at the end of the summer" return date, how best to book? 2 one ways? (this would be far less than a unrestricted full fare RT). Is there still a way to do an open date return?