especially october and november. GS and CME options are missing these months. then in 2010, Feburary is missing...whats goin on? and BWLD options for 2010 dont expire till march, skipping over Janurary.
Here is an article on expiry cycles http://www.investopedia.com/articles/optioninvestor/03/090303.asp
They are not missing, options are listed in cycles, read the article suggested or visit the exchange's website.