A nice genuine samurai sword and not a Chinese copy for a change. It is impossible to date the blade accurately from images when it is unsigned. It would take an in hand examination by a trained appraiser. The mounting is
19th century but the blade is older as the three holes indicate three seperate mountings. When making a remount, more care would have been made for a signed quality blade to not punch extra holes in the nakago. The blade is definitely Edo period(post 1600)and likely late 17th century. As there was a long period of peace during the Edo period, sword making fell off and few were made during the 18th century.