Chicago Cubs:

Before signing a developmental agreement with the Kane County Cougars in 2012, the Cubs had a Class A minor league affiliation on two occasions with the Peoria Chiefs (1985–1995 and 2004–2012). Ryne Sandberg managed the Chiefs from 2006 to 2010. In the period between those associations with the Chiefs the club had affiliations with the Dayton Dragons and Lansing Lugnuts. The Lugnuts were often affectionately referred to by Chip Caray as "Steve Stone's favorite team." The 2007 developmental contract with the Tennessee Smokies was preceded by Double A affiliations with the Orlando Cubs and West Tenn Diamond Jaxx. On September 16, 2014 the Cubs announced a move of their top Class A affiliate from Daytona in the Florida State League to Myrtle Beach in the Carolina League for the 2015 season. Two days later, on the 18th, the Cubs signed a 4-year player development contract with the South Bend Silver Hawks of the Midwest League, ending their brief relationship with the Kane County Cougars and shortly thereafter renaming the Silver Hawks the South Bend Cubs.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". When did the Cubs announce a move of their top class A affiliate from Daytona to Myrtle Beach?
September 16, 2014