St Marys ga fourth of july

this year St Marys GA is celibrating the fourth of July on the 3rd because the Fourth falls on a Sunday this year. the city of st Marys said that they didn't want to interrupt church on Sunday with all of the festivity's and fire work display.I dont understand this beacouse the fourth of july is the celibration of our countries independence wich was not on the third of july.