How to write a date in Roman numerals

Most people who look this up are about to put the date somewhere permanent: a tattoo, a wedding ring, a sign, a watch caseback. So this page is built around getting it right the first time. If you want the basics of the numeral system itself, start with our Roman numerals explained guide.

Step 1: settle the date order

This is the mistake that ends up on skin. The same date written in Roman numerals looks completely different depending on the order you choose, and nobody reading it can tell which one you meant.

For dates like 5 March, the two versions are indistinguishable to a stranger: V.III could be 5 March or 3 May. If the order matters to you, pick one and stick with it, or write the month as a word.

Step 2: convert each part on its own

Never try to convert the whole date as a single number. Do three small conversions.

Months

Days

Days run from I to XXXI. The ones people most often get wrong are the fours and nines: IV (4), IX (9), XIV (14), XIX (19), XXIV (24), and XXIX (29). Thirty is XXX and thirty-one is XXXI.

Years

Break the year into thousands, hundreds, tens and ones. Every year from 1900 to 1999 starts with MCM; every year from 2000 to 2099 starts with MM.

Step 3: join the parts

Romans never wrote dates like this, so there is no ancient rule for separators. Dots are the most common modern choice (XIV.X.MCMXC), but dashes, spaces and vertical bars are all fine. Pick one and use it consistently. Without any separator, XIVXMCMXC is genuinely unreadable, even to people who know numerals well.

Step 4: check it backwards

Before anything is printed, engraved or inked, convert each part back into ordinary numbers yourself. It takes thirty seconds and catches nearly every error. Don't rely on the artist or the jeweller to check it; many won't.

The mistakes that end up permanent

• The wrong date order. Covered above, and still the most common problem.
• IIII instead of IV. Clock faces often use IIII by tradition, but in a written date IV is the standard form.
• MIM for 1999. Some converters output it. The standard form is MCMXCIX.
• A zero. Roman numerals have none. A day like "05" is simply V.
• Mixing up similar letters. In some fonts I and l, or V and U, look alike. Choose a clean serif font so each character is unambiguous.
• Converting the year as two numbers. 1990 is MCMXC, not XIX and XC glued together.
• Losing a character in the design. Long years like MCMLXXXVIII (1988) get cramped. Count the letters in the final artwork against your written version.

Worked examples

How Romans actually wrote dates

Here is the fun part: a Roman would not recognise any of this. Romans counted days backwards from three fixed points in each month, the Kalends, Nones and Ides, and named years after the two consuls in office rather than numbering them. The Ides of March, the day Julius Caesar was killed, is a leftover of that system. The numbered-date format is entirely modern, which is exactly why there's no official way to punctuate it.

Sources: standard references on the Roman numeral system and the Roman calendar. The separators and date orders described here are modern conventions, not ancient practice, so there is no single correct style beyond consistency and clarity.

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