The quality of service at a nail salon on Sundays may not necessarily be the same as on weekdays. This can depend on various factors, such as the number of staff members working, the level of demand, and the policies of the nail salon. However, many nail salons strive to maintain consistent quality of service regardless of the day of the week. It's best to check reviews or ask for recommendations from friends to find a nail salon that consistently provides high-quality service, regardless of the day of the week.