If you need to specify how much time a Learner must spend in a course in order for it to be completed, click on the course and then navigate to the Course Settings tab.

Scroll down to Overall Time Required to Pass and enter the required number of minutes. Leave it as 0 if no specific time is required.

If you also have time requirements set on individual modules, both the individual and the overall time requirements must be met before the course is considered complete.