“Shall” does not translate very well.
Scott from Tyner Blain presumably read the post on optimal options for sleep schedule.
At least he apparently had some time left to get to the bottom of a problem.
Scott translated the word “Must” from English to 41 other languages, and translated the found word back. For 41 of 41 languages this exercize returned the word “Must”.
He als found that the word “Shall”, translated from English to another language and than back, does not translate back into “Shall” most of the time.
It is translated in Will, Should, Must, To be, We, I, Point, Has and Going. His advice: “You need to use the word must when writing requirements to avoid ambiguity”