Septembrist \sep-TEM-brist\ , noun;
1. A person who instigated or took part in the September Massacre
What a perfect word for the last day of August, no?
This word is first attested in 1793 in reference to the massacre of political prisoners that took place in Paris from September 2nd through the 6th in 1792. At the time, the French called them septembriste or septembriseur. Later the Portuguese adopted the word for their (successful) insurrection in September 1836 and altered it to stembrista.