Suha's Day of Thunder

First celebrated August 2667
The Day of Thunder is a celebration on the planet Suha commemorating the first time that their super weapon the Red Horizon Singularity Gun was fired successfully. 
The singularity sub-munition was used to compact a Fleshshaper Battlemoon at Acastus. It was considered a complete success in every sense of the word, as the shell performed perfectly. 
Their life's work given legitimacy, the planet celebrates by honoring the graves of those who had worked on the gun in the past, celebrating the current technical crew as kings and queens for a day, and otherwise celebrates being part of a world capable of producing such technological works of wonder.