Calendar class related error in latest Processing 2.0b7

I'm testing the code "M_1_6_01_TOOL" from the book Generative Design, and the latest Processing 2.0b7 will give me error related to the Calendar class, but the code run smoothly in 2.0b6

source code:
http://www.generative-gestaltung.de/M_1_6_01_TOOL

Anybody encounter similar problem?