Your NSS Bookstore is open 8 am to 5 pm, Central Time, Monday through Friday, year-round, except for federal holidays and the events below. You can visit your NSS Bookstore at the following events in 2013! SERA CAVE CARNIVAL May 3-6 bhamgrotto.org/sera2012 NSS "MAYACON 2012" CONVENTION June 25-29 nss2012.com TAG FALL CAVE-IN October 4-7 tagfallcavein.org