The 2013 season resulted in much as the same the year before. Shortly before the trade deadline, the Cubs traded Matt Garza to the Texas Rangers for Mike Olt, C. J. Edwards, Neil Ramirez, and Justin Grimm. Three days later, the Cubs sent Alfonso Soriano to the New York Yankees for minor leaguer Corey Black. The mid season fire sale led to another last place finish in the NL Central, finishing with a record of 66-96. Although there was a five-game improvement in the record from the year before, Anthony Rizzo and Starlin Castro seemed to take steps backward in their development. On September 30, 2013, Theo Epstein made the decision to fire manager Dale Sveum after just two seasons at the helm of the Cubs. The regression of several young players was thought to be the main focus point, as the front office said Dale would not be judged based on wins and losses. In two seasons as skipper, Sveum finished with a record of 127-197.

Answer this question, if possible (if impossible, reply "unanswerable"): When did Theo Epstein made the decision to fire Dale Sveum?
September 30, 2013