You can find the full FMCSA guide to hours of service on the web. Pages 3 and 4 explain hours of service regulation.
It's 36 hours to do a reset if your a Canadian driver. Not sure of Americans have to show the 36 if up in Canada. I have oilfield exemption so don't follow regular log book rules.
American do have to show the 36 if in Canada. I run provincial, no resets required, so can't answer the original question.