Question: Among the working days from Monday to Saturday, which businesses with the category names work the most days?
SQL: SELECT T2.category_name FROM Business_Categories AS T1 INNER JOIN Categories AS T2 ON T1.category_id = T2.category_id INNER JOIN Business_Hours AS T3 ON T1.business_id = T3.business_id INNER JOIN Days AS T4 ON T3.day_id = T4.day_id GROUP BY T2.category_name ORDER BY COUNT(T3.day_id) DESC LIMIT 1