Rat Day
From RocksfallWiki
House Rat left the sewers in 2197. Still a marginalized group as recently as the beginning of Emperor Marl Kizer's reign in 2247, members of House Rat formed a grassroots movement to have a holiday added for their own House, similar to those celebrated for the other Houses at the turn of each year.
Originally campaigning to have the holiday celebrated on the 20th of Eleventh-month, which is the anniversary of their departure from the undercity, the Imperial Council prevailed upon them to add it on to the end of the Festival Days. Rat Day has been celebrated on the First of First Month since 2253, though it is not recognized as an official Imperial holiday.