I tried that, but when I researched it a bit more I realized there was more to writing dates in Irish then simple translation. For example in Scottish Gaelic that date is written as:
An ceathramh deug dhen mhart
Note that there are hardly any Gaelic speakers (Irish or Scottish) who don't also speak English and write dates using mostly numerals. I can't really imagine why someone would take "14th March 2009" and not retain the numerals when translating it into Gaelic. It would be 14 Márta 2009, incidentally.