AlthoughmostuniversitiesintheUnitedStatesarerunonasemestersystem,whichoffersclassesinthefallandspring,someschoolsobserveaquartersystemcomprisedoffall,winter,spring,andsummerquarters.Theacademicyear,SeptembertoJune,isdividedintothreequartersofelevenweekseachbeginninginSeptember,January,andMarch,thesummerquarter,JunetoAugustiscomposedofshortersessionsofvaryinglength.Studentsmaytakeadvantageoftheopportunitytostudyyeararoundbyenrollinginallfourquarters,Moststudentsbegintheirprogramsinthefallquarter,buttheymayenteratthebeginningofanyoftheotherquarters.