Here's a simple moon phase calendar for quick testing:
http://www.moonconnection.com/moon_phases_calendar.phtml
Here's NASA's moon phases for 2000 BCE to 4000 CE for serious testing:
http://eclipse.gsfc.nasa.gov/phase/phasecat.html
Here's some maths for devs to rip off:
http://www.ben-daglish.net/moon.shtml
http://www.koniaris.com/lunar/fraction.html