@Pyrrho,
Pyrrho;124143 wrote:Why do you drive on the left side of the road? It is customary. Logic has nothing to do with it.
Of course he wasn't meaning that it has anything to do with formal logic, or the study of inference or syllogism. Sometimes people use the word "logical" synonymously with "reasonable" or "consistent" or "ordered". For instance, people say things like, "The decision to do X was a
logical course of action" or "That's not a
logical order". In regards to this post, he just means the way Americans write dates is not following an order from a smaller unit to larger, or a larger unit to smaller.
And not every norm is arbitrary, or without reason, as you seem to imply (I got this impression because you use the example of driving on the left side of the road, a norm which, on the surface, doesn't seem to have any good reason for being this way). There are often good reasons for why things are the way they are, and many may even refer to some of these good reasons as being logical.