I decided to ask Copilot why they used improper Roman numerals.
Why “improper” numerals appear on buildings
Stylistic balance: Using MDCCCCIV (1904) instead of MCMIV avoids the subtractive notation and creates a longer, more symmetrical inscription. Architects sometimes preferred the visual weight of extra letters to fill space evenly across a façade.
Traditional precedent: Just as many clocks use IIII instead of IV for the number 4, builders followed conventions that emphasized clarity and tradition over strict correctness. This practice dates back centuries.
Ease of carving: Stone carvers often favored additive forms (like CCCC instead of CD) because they were straightforward to lay out and less prone to misinterpretation.
Regional or cultural norms: In some places, additive numerals were more common in inscriptions, especially in the 19th and early 20th centuries. MDCCCCIV was widely accepted at the time, even if grammatically “incorrect” by classical Roman standards.
Religious or symbolic reasons: In certain contexts, subtractive forms like IV were avoided because “IV” was also shorthand for Jupiter (IV = IVPPITER). Churches and civic buildings sometimes steered clear of that association.
That is more tricky, it depends on the earths rotation and its time to orbit the sun.
The approximate figure is 364 1/4. earth rotations per orbit
We arbitrarily define it as 364 for 3 years then 365 in a leap year
so
if days are numbered 1 to 364 it is
364 - 1 +1 = 364
if days ard numbered 0 to 363 it is
363 - 0 + 1 = 364
so it does not matter what the number base is…we can still count the number of days in an interval
I have been reading … apparently using ‘proper’ roman numerals allows for easier arithmetic ..?.. the abasus was designed for use with ‘proper’ roman numerals. Using an abacus you are supposed to be able to add and multiply roman numerals without knowing any times tables… so roman numerals were used for commerce… supported by the abacus.
Noone does arithmetic with building inscriptions … so thdy csn bd improper.
Here is a fun fact.
In 1582 the calendar went from October 4 to October the 15 skipping 11 days.
I knew about the skip, but had to look up when it happen.
Yes, 1 century is 100 years.
But as Neville pointed out, 1 year is not exactly 365 days. And a year is define as one rotation around the sun by the earth. So yes, our calendar is off by a very little bit.
Here the rest I read about our calendar.
“Julian calendar, introduced by Julius Caesar, added a leap day every 4 years.”
This was too many days added to the calendar over time.
“Pope Gregory XIII introduced the Gregorian calendar in 1582”
This was when the calendar lost the 11 days and the new leap year rules were establish to keep the earth’s rotation around the sun in sync with the calendar.
A year is a leap year if is is dividable by 4 except
if it is dividable by 100 except
if it is dividable by 400.
“The 100‑year and 400‑year corrections fine‑tune the calendar so it stays accurate over centuries.”
I would suppose accuracy is define as the earth being in the same spot around the sun year, after year, after year.
No. Counting years in a century has nothing to do with days in a year and nothing to do with astronomy.
You might be counting years that vary in length, but it is still just counting.
If you wanted to count the number of days in a century, that would be different for each century… because the earths rotation and orbit vary.
Gregorian. I dont think it matters, except Julian calendar does not have leap years.
SORRY THAT IS WRONG… HOWARD CORRECTED ME, SEE BELOW
Sorry and it’s trivial at this point, but from what I read the Julian calendar added a leap day every 4 years. That’s why the calendar was so out of sync by 1582,
You are right… my mistake. The Gregorian calendar took one leap year away each century. You rescued me again.
The earth’s rotation and orbit are rather poor timekeepers.
