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Wow! It actually makes sense!
(i.imgur.com)
Professionals have standards! Community for all proponents, defenders and junkies of the Metric (International) system, the ISO standards (including ISO 8601) and other ways of standardization or regulation!
Both are confusing. Let's use colours instead:
Red = hot, wear shorts and a t shirt
Blue = cold, grab a jacket
Pretty intuitive without any prior knowledge.