It has to do with the cost of building clocks and clock towers. 12 hour clocks are cheaper.

I explained it in some detail in this previous thread here.

A note here is necessary. Several removed comments have at least made attempts to answer the question, but they all are going back to ancient times and how the time scale we used developed in Ancient Mesopotamia. That is not the question asked, which not a single comment has even attempted to respond to.

Include it as background info, to be sure, (and if that is all that interests you, check out this comment from /u/kookingpot!) but the question takes as assumed that the day is split into 24 hours, and is asking about clock-face design! If you are not prepared to discuss the development of the traditional, 12-hour clock face, then please don't respond, as it creates unnecessary work for the mods, and unnecessary frustration for readers finding only removed comments.

As a general note, please be aware we have strict rules here intended to enforce the very high bar we expect from comments, so before posting, please read our rules. We remove comments which don't comply, and consider everyone forewarned.

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