It's important to note that opinions on "bad days" can vary greatly from person to person. However, some common factors that people might consider when labeling a day as "bad" could include feeling particularly stressed, facing unexpected challenges, experiencing conflict with others, or dealing with difficult circumstances.

If you're looking for general patterns or astrological interpretations of potentially challenging days in September, it's worth researching information on lunar phases, planetary movements, or astrological forecasts specific to this month. Keep in mind that these are based on interpretations and may not resonate with everyone.

Overall, it's important to approach each day with a positive mindset and resilience, as even challenging days can provide opportunities for personal growth and learning. Remember that difficult days are a normal part of life, and it's okay to seek support from friends, family, or professionals if needed.