Link to interpretive information from ALPA:
ALPA Guide FAR 117 – Jul 2019 5a
ALPA Guide-to part 121 subpart Q, R and S-FTDT-Limits-June-2004 ed 6A
Captain Pierson is an airline pilot for a major U.S. carrier, based in New York. He has been an airline pilot for 15+ years, and have been working in the aviation industry for nearly 20. and has written two books, the first being, Pilots In Command: Your Best Trip, Every Trip, was published in 2014 by ASA. Captain Pierson may be contacted via his web site: krispierson.com
How You Can Ensure FAR 117 Compliance by Kris Pierson.