The IMM dates are the four quarterly dates of each year which EuroDollar and Foreign Exchange futures contracts and option contracts use as their scheduled maturity date or termination date. The dates are the third Wednesday of March, June, September and December (i.e., between the 15th and 21st, whichever such day is a Wednesday). IMM stands for the International Monetary Market. This choice of date – middle of month and middle of week – minimizes issues with date rolling, as holidays are very unlikely to make the closest business day in another week or other month.