For dates, you are perhaps better off using existing libraries than redefining your own.
The main international library that I am aware of with multilingual calendar-related strings is International Components for Unicode (ICU) - https://en.wikipedia.org/wiki/International_Components_for_Unicode The main one for calendars is 'tz' - http://en.wikipedia.org/wiki/IANA_time_zone_database These are the de-facto libraries used by desktop and mobile Linux systems. While they have serious issues and TZ in particular appears to be loaded with bureaucratic, cultural and technical baggage of bygone eras, they are the 'standard solution' in this space. Both already have good perl integration, no doubt. - Walter
