Hi David,
Are you actually talking about a survey-type of activity (such as Moodle's Survey or Questionnaire plugins) or about a test/quiz activity type?
I can only answer for Questionnaire: there is no time-recording feature feature in this module nor any plans to have one, unless a fair number of users say it is indispensable to them. You might open an issue in the bug tracker so people can vote for it.
Joseph