lunar calendar control

[Happy YN]

We've all seen those pop up calendars which allow one to select any date which inserts itself into a textbox. I would like to create one but for the Jewish (lunar) calendar.This is made up of months (usually 12 but sometimes 13). Each month is either 29 or 30 days. (10 months are fixed and 2 are variable). I have a list of all dates for the next few years. Any idea how I could build this? Thanks