Hi there! You can change the timing and pacing settings of your course by going to "Administer students" > "Timeline" and changing your course to "Scheduled". Here, you will be able to set a start date for your course and decide when to make certain modules and pages available. You can also set due dates on specific pages.

However, you can't actually set an end date for the whole course here. What you can do is notify the students when the end date of the course will be (on the intro page and homepage for example) and then manually turn your course offline on that date.

You can turn your course offline by going to "Course Setup" > "General" and flicking the bar next to "Course status" to "offline"