Currently these different Moodle activities display their "availability dates" in different ways. This should really be standardized.
I am not talking about the way that those activities are displayed in the student's course calendar, that is another matter.
Here are such display messages for instances of activities which are not yet available and have a closing date.
A test assignment
This assignment will accept submissions from Saturday, 2 February 2019, 12:00 AM
Due date Wednesday, 6 February 2019, 12:00 AM
Time remaining 5 days 12 hours
A test Quiz
The quiz will not be available until Saturday, 2 February 2019, 11:09 PM
This quiz will close at Tuesday, 12 February 2019, 11:03 PM
This quiz is not currently available
A test lesson
This lesson will be open on Saturday, 2 February 2019, 11:50 AM.
A test questionnaire
This questionnaire will not open until Saturday, 2 February 2019, 11:21 PM.
As can be seen, Assignment gives the most complete info, followed by Quiz. Questionnaire and Lesson only give the opening date info, not the closing date.
It should be trivial to add the closing date info for Questionnaire, such as in:
A test questionnaire
This questionnaire will not open until Saturday, 2 February 2019, 11:21 PM.
This questionnaire will close on Tuesday, 5 February 2019, 12:00 AM
by adding the relevant line in file mod/questionnaire/view.php somewhere between lines 70 and 130; and also adding the relevant string in the lang file.
Mike, what do you think?