Joda Time is a Java library that provides a replacement for the Java date and time classes. Since it’s a Java library, it integrates easily with Grails.
I’ve been using CloudFoundry as a PaaS solution for a Grails application for several months now. I tested it out with a small test application at first and it worked great but as I deployed a larger application I had regular issues. In particular, I had issues with failures in updating the application and starting the app.