As of the last known update to the New Britannia sky, there is a certain bug where the sky resets itself every year.  As such, this simulation of the planetary orbits around New Britannia is accurate for every year until this bug is fixed.

It should be noted that as of this posting (Aug 2nd), Portalarium will be working on the astronomy “soon”.  This should still serve as a good reference but in the future we hope to provide tools that will help predict planetary motion for any date past, present or future.