1, 2, 3, God, 5, 6 - Why Do Clocks Use IIII Instead of IV?

Have you ever wondered why almost every modern clock or watch with Roman numerals uses ‘IIII’ instead of ‘IV’ to represent 4 o’clock? There are several possible explanations.

One likely explanation is that the strict use of IV instead of IIII wasn't common until after the Middle Ages. Clocks and watches are patterned after sundials, which were in use long before the Middle Ages.

Another likely explanation is that using IIII brings more symmetry and balance to the dial. The four-character form IIII is "heavier" than the IV and creates a visual symmetry with the "heavy" VIII on the other side. Another symmetry is achived because the I symbol would be the only symbol in the first 4 hours of the clock, the V symbol would only appear in the next 4 hours, and the X symbol only in the last 4 hours.

A practical reason can be that IV is difficult to read upside down and on an angle, particularly at that location on the clock (can be confused with VI).

Another reason is related to the molds used to cast the metal numbers. Using four I's instead of one I and one V will total in 20 I's, 4 V's, and 4 X's per one clock, so all the numbers could have been manufactured using one mold of 'I I I I I V X' four times.

There are some stories of several kings objecting to the IV form, but these seems unlikely.

But the most surprising explanation I’ve found would have to be this: In ancient Latin, ‘I’ was used instead of a ‘J’, and ‘V’ instead of a ‘U’. So ‘IV’ was an abbreviation for the Roman god Jupiter (IVPPITER) and using IV could have been considered sacrilegious. I guess the Romans thought 1, 2, 3, God, 5, 6… looks too weird on a sundial.

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p.s. Bringing your pet elephant to work is a bad idea, even if it is Casual Friday.