I am new to futures trading. The eurodollar futures' contract months listings is defined as "Mar, Jun, Sep, Dec, Forty months in the March quarterly cycle, and the four nearest serial contract months." What are the 'Forty months in the March quarterly cycle'? And what are 'the four nearest serial contract months'? I see similar contract months or called delivery months in short sterling futures, "March, June, September, December, and two serial months, such that 22 delivery months are available for trading, with the nearest three delivery months being consecutive calendar months." This time what are the 'two serial months' and what are the '22 delivery months'? Thank you.