Seeing as this name is derived from Greek δυσμη (dysme) meaning "sunset", its original spelling in Greek should be Δυσμας (Dysmas), with Dismas being a variant (if not anglicized) spelling.With that said, the use of Dismas as a given name has not solely been restricted to Judeo-Christian Legend, in that it has been used in real life for real people as well. For example, there was the Bohemian composer and violinist Dismas Hataš (1724-1777) and the Czech baroque composer Jan Dismas Zelenka (1679-1745). In the Netherlands, in the year 2014 there was a total of 10 bearers (of all ages) in the entire country. The name has also been used in other countries, such as Austria, Germany and even the United States of America. Yes, the name can certainly be considered old-fashioned (and therefore rare) nowadays, but there is no question that it has been used frequently in several countries in older times.- https://it.wikipedia.org/wiki/Disma_(nome) (in Italian; mentions the Greek spelling among others) - Dismas Hataš: https://en.wikipedia.org/wiki/Dismas_Hata%C5%A1 (in English) - Jan Dismas Zelenka: https://en.wikipedia.org/wiki/Jan_Dismas_Zelenka (in English) - http://www.meertens.knaw.nl/nvb/naam/is/Dismas (in Dutch) - https://familysearch.org/search/record/results?count=20&query=%2Bgivenname%3ADismas.
The man in question does not have a known name, and it was not until the twelfth century in the Gospel of Nicodemus that 'Dismas' was given to him. (His name is sometimes spelled Dysmas or only Dimas, or even Dumas).The name of "Dismas" was adapted from a Greek word meaning "sunset" or "death." The other thief's name is given as Gestas. The apocryphal Arabic Infancy Gospel calls the two thieves Titus (Dismas) and Dumachus.In the Russian tradition the Good Thief's name is Rakh (Russian: Рах).