I am programming a stock tracker application with Yahoo's finance API. At the beginning of this month I noticed that the information provided by Yahoo on the commodities were wrong. So I looked up the symbols on Yahoo's finance website and realized, that the symbols for the upcoming futures changed.
Due to the fact that I'am not a finance guy, I have no idea what the pattern might be behind the changing commodity symbols. I'am pretty sure that there is a pattern, because the symbols for September are all ending with a U (GCU16.CMX, SIU16.CMX, HGU16.CMX etc.).
So we have a monthly changing symbol pattern similar to:
XX + Single letter for the month + Year + . + Exchange
Does anyone have an idea, in which way the "Single letter for the month"-part is changing in the symbol, so that I can automate those one letter changes in my programm?