"Six ways from Sunday" explained

I encountered the phrase this past week and knew the sense of the idiom, but couldn't concoct a logical derivation.  Found one answer at Grammarist:

The idiom six ways from Sunday means in every way possible, having done something completely, having addressed every alternative. Six ways from Sunday seems to have its origins in the middle eighteenth century as the phrases both ways from Sunday and two ways from Sunday. These earlier phrases referred to the eye condition known as strabismus, where someone’s eyes do not focus in unison, giving the appearance of looking in two different directions. From there, the terms... gained the figurative meaning of looking at something askew. By the mid-1800s... the meaning evolved to mean to be at a loss. The phrase evolved once again in the late 1800s in America to mean every way possible. One still finds many varieties of the phrase, the number in question might be six, seven, nine or a thousand, the preposition might be from, to or for, but the day referred to in the idiom is always Sunday and the idiom carries the same meaning, which is in all ways possible.