This program can build custom Gen 5 Pokémon Distribution ROMs from a .pgf event file and a clean copy of the Liberty Ticket distribution ROM (both not included).

Currently(v1.1.1) you can:

Change the .pgf event file
Create your own .pgf file
Change the date limit
Change which games can receive the event
Change which games region can receive the event (partially tested | only tested with English and French copies)
Change the event text that appears upon receiving