Normally, matsu no uchi (the period in which matsu kazari (pine decoration) is displayed during the New Year) should last up to Koshogatsu; even today, matsu no uchi lasts until Koshogatsu of January 15th in the Kansai and Kinki regions.
なお、この小正月までが本来の松の内であり、関西や近畿地方では現在でも1月15日の小正月までが「松の内」である。