Almanacs follow the moon's position to determine the best days to perform certain tasks for certain outcomes.
Trim hair to increase growth:
November 16, 17, 18, 21, 22, 23, 26, 27, 30
Trim Hair to decrease growth:
November 2, 5, 6, 9, 14, 15
I've followed almanacs all my life and I've been pleased with the results. I'm sure that if a person cuts his/her hair on the wrong phase, all will be fine but as I try to walk in sync with nature, I love being in balance with nature.
If you decide to use the dates, let me know if you feel it was successful!
Disclaimer: Following moon phases has worked for me and are my experiences.
(click photo to enlarge)