How may I schedule when comments can be Opened and Closed? I've been tasked to set up a Q&amp;A styled project where we invite an industry leader, subject matter expert (SME) to answer questions for hopeful students in the same field. The individual requesting this project is a fan of reddit's Ask-Me-Anything styled interviews. So, yes, that is a big driver of this project. 

We'll have a period of a week where the students can ask questions and two weeks where the SME can respond to those questions. In the fourth week, both can further respond with follow up questions or expanded responses. After that, the conversation will be available as read-only archive with nothing new added. I'm thinking nested comments would be sufficient. 

Can I tell Drupal to open and close comments on certain dates, or even use a date field of when comments should be closed?
I'm okay with either using a contributed module (I haven't found one), Rules (I've not used very much), or custom code (My default, but there are people much smarter than me who have probably already done this better).
That should be as simple as:

function MYMODULE_node_view($node, $view_mode, $langcode) {
  if (/* Your logic to determine that comments are closed here */) {
    $node-&gt;content['comments']['#access'] = FALSE;
  }
}


(it'll probably need to be tweaked for your exact requirements, have a look at what else lives in $node-&gt;content['comments'] if you want to hide the form/existing comments separately).