Date in Roman numerals
A wedding, a birth, an anniversary. Pick the date, choose the layout, copy it.
How a date becomes Roman
There is no such thing as a Roman date format. The Romans dated things by consul and by counting backwards from three fixed points in the month, which nobody uses today. What we call a Roman date is a modern habit: take the day, the month and the year, convert each one on its own, and put them next to each other.
Take 14 July 2018. The day is XIV, the month is VII, the year is MMXVIII. Joined together that reads XIV · VII · MMXVIII. Nothing about those three parts says which is the day and which is the month, so the order is a choice you make for your reader, not a rule you follow.
Two things trip people up. There is no zero and there are no leading zeros, so the fifth of a month is V and never 0V. And the separator is up to you: a dot, a middle dot, a slash, or no separator at all when the three parts are stacked on three lines, which is how most engraved work does it.
The largest year the standard symbols reach is 3999. That is far beyond any date that ends up on a ring, a print or a tattoo, so you will not run into the limit.