Check off the SET TIMER box if you want to limit the time the student has available to answer a question / assignment. The time you set is by standard in MINUTES:SECONDS. 1:00 means one minute. 1:00:00 means one hour.
IMPORTANT: Only have one timed item in each section. Make it visible as soon as the page load, so that the student knows what is required as soon as possible. Preferable warn the student at the end of the previous section.
Set the time on an item:
This is what the timer looks like in the course: