Thirty-three days begins a habit. A second round gives it time to settle. Here is how to run Days 34 to 66, and how to share the practice with someone else.
In the habit research behind reference [5] in the book (Gardner, Lally and Wardle, 2012), a new daily behaviour took about 66 days on average to feel automatic, and people differed widely. You can read the paper free: Gardner, Lally and Wardle (2012).
That figure is an average across many people and habits. It is not a promise for you. It is a good reason not to stop at Day 33, and a second round gives you a clear way to keep going.
Each edition follows the same 33 days with a different source of wisdom beside the science. The editions are listed alphabetically, and each title opens that edition's page, with its Kindle link once it is on sale.
A practice is easier to keep when someone is breathing beside you. Gift a copy to a friend, or to someone you are working to make peace with (Day 14 of the book is for exactly that), and start Day 0 together.
The General edition is on sale now: open its Kindle page and choose Buy for others. Every other edition has its own Kindle link on its page in the list above, as soon as it is on sale.
I would like to know what the second round does for you, and what it does not. Share your story in the short story form, or suggest changes for the next edition in this form. You choose whether I may quote you.