 In Germany , " <unk> Tag noch ! " , the German phrase for " have a nice day " , is being used more frequently by its vendors and waiters . German author Hyde Flippo wrote that many Germans deem " have a nice day " to be affected and shallow . Flippo further opined that the phrase is an appropriate example of culturally improper language . He compared it to smiling arbitrarily at a German person which would give the impression that the smiler is a " little simple @-@ minded or not quite ' all there ' " . Writing that Germans prefer " Auf Wiedersehen ! " or " <unk> ! " ( both meaning " goodbye " ) — which German shopkeepers frequently use — to " dubious wishes for a nice day " he opined that that is why Germans generally favor visiting a small shop instead of a large department store . 
