Dus Lakshan (Dus Lakshan Parva) in Jainism refers to the ten signs or characteristics that are highlighted for spiritual practice and proper conduct. There is no universal, single “7th day” that is fixed across all Jain traditions. Different communities (Digambar and Śvetāmbār) may emphasize different aspects of the ten lakshanas, and local observation calendars can vary.

If you can share which tradition (Digambar or Śvetāmbār), or the specific local festival/ritual you’re thinking of, I can give a precise explanation of what the 7th lakshana means in that context.