The first harbingers of Christmas arrive in October when jarring sales and decorations follow fast on the heels of summer.
Does the word jarring here mean annoying, or early/preliminary?
jarring (adjective): causing a strong emotional reaction because of unexpectedness
the jarring news that major financial institutions were on the verge of collapse.
disagreeable to one's aesthetic or artistic sense
the final chord of that song is too jarring for me.
Jarring implies "opposite if comfortable". Its negative in the sense its an uncomfortable or disjointed sale process.