One person might believe that one day is more important than another. And another person might believe that every day is the same. Each person should be sure about his own beliefs in his own mind.
I am in the Lord Jesus. And I know that there is no food that is wrong to eat. But if a person believes that something is wrong, then that thing is wrong for him.
But not all people know this. Some people have had the habit of worshiping idols {\cf2\super [49]} until now. So now when those people eat meat, they still feel like it belongs to an idol. They are not sure that it is right to eat this meat. So when they eat it, they feel guilty.