The latest version of lubridate offers some powerful new features and huge speed improvements. Some areas, such as date parsing are more than 50 times faster. lubridate 1.2.0 also fixes those pesky NA bugs in 1.1.0. Here’s some of what you’ll find: Parsers can now handle a wider variety date formats, even within the same 
Zero Inflated Models and Generalized Linear Mixed Models with R.
Zuur, Saveliev, Ieno (2012).
