Towards the end of the Application Case creation process, you will encounter the following page in the publishing section of the activity creation setup:
Asynchronous type: All students will take the activity at a different time.
Open period during asynchronous activities: This is the period that your activity will remain open during asynchronous activities.
Activity duration during asynchronous activities: This is the time that your activity will remain open for once the student starts the activity. You have the ability to set a time limit for your activity by toggling the option to yes/no during this process.
Once you're ready to publish your activity click on the Publish Activity button.