The Roman Martyrology is a recent discovery for me, and one that I know I will enjoy very much. For one thing, it has cured me of a long-standing bit of ignorance.
In our communities, each friar gets an annual celebration. For those who received names in religion, the name day is celebrated. For those of us who entered after the end of religious names (as well for those who reverted to their baptismal names when given the chance), we celebrate birthdays like the rest of the world.
I was always baffled by these name days. A lot of the religious names among us aren't saints you've ever heard of. They aren't in the liturgical calendar as most of us know it. So where did these name days come from? Well, now that I know the Roman Martyrology, I have found the source. For example, today over at the old friars' home they are celebrating the name day of Fr. Joel, whose name in the world was Dan. And there it is in the Martyrology for July 13:
In Palæstína sanctórum Joélis et Esdræ Prophetárum.