Sundials

The four o'clock problem: IV or IIII?

On the faces of clocks and sundials that use Roman numerals, four o'clock is often denoted as IIII instead of IV, as it should be. Why is that, is a frequently asked question.

A number of excellent websites discuss this question extensively:

• Donn Lathrop: To IV, or not to IV: that is the question

• Gordon Uber: Roman IIII vs. IV on Clock Dials

• Paul Lewis: Clocking the Fours. A new theory about IIII

Two main points taken from this discussion are:

• A common explanation for the use of IIII on clock faces is that it balances the 'heavy' VIII across the face. Hence, an aesthetic argument. And as clock makers often also constructed sundials, this usage is being found there also.
• Rules on how to write Roman numerals are relatively recent; life in the Roman Age and the Middle Ages was not so formalistic. So everyone could do things the way they liked.

But how about the year (1742) on the Frenswegen monastery in Germany (between Nordhorn and Ootmarsum)? By the way, Ootmarsum is exceptional, as the clock on the church has IV instead of IIII!