Single word for "an understanding based on cultural norms"?

Maxim or adage might work, though in your example, you're talking more of an implied understanding (about Monday) than an express statement, and these two are used more regarding overt expressions. Platitude is another option, though you run into the same problems: what you're wanting is the concept behind an unstated understanding.

A German word might be the following (from Worthless Word of the Day):

einfuhlung - [G.] understanding so intimate that the feelings, thoughts, and motives of one person are readily comprehended by another (this would be a stretch to apply, but it would be accurate, since the conversational participants had an einfuhlung on this particular matter regarding Mondays)

One more option: enthymeme. (Definition below)

That is a good question - starring it!

Words like maxim, platitude, axiom, and truism seem to carry a definitional element beyond just cultural norms. These words have an implication there is some self-evident truthfulness about the matter at issue. I do not think your examples of cultural understandings around Monday and Friday mornings have a self-evident characteristic to them.

If we are to explain understandings based solely on cultural norms, I think two better words might be "stigma" (in the case of a negative shared understanding of something) or "stereotype" (which could evoke either a positive or negative impression). I think what you have described are "stereotypical" understandings about Mondays and Fridays which Bob's comments allude to. In addition, Mondays are "stigmatized" as being bad days.

I'm thinking "truism" might be appropriate......doesn't really have the cultural component but that is the closest I can come!

Edit: Another possibility is "proverb" (a simple and concrete saying popularly known and repeated, which expresses a truth, based on common sense or the practical experience of humanity).....that is the definition I saw listed for that word, although I still think truism is more fitting :-)

No duality, no ideas! searching for cohesion isn't any distinctive then wishing all of us might particularly like all of us each and every of the time. mind's eye is a superb element because of the fact it will boost the question: why no longer? and then we seek for the respond. sometime plainly why no longer leads to understanding something that has on no account occurred in the previous, and at different situations plainly there is an fairly solid clarification for why no longer! Love is the only reconciler of duality, yet that style of love is for us to flavor purely. that's reserved for the condition for the potential of love--and that probability is likewise what makes duality accessible.

ideology