Hinduism has lots of rituals, traditions & cultures. Some rituals & traditions now become superstitions. But some rituals or traditions are kinds of superstitions but those are followed till now by many people of India. From ancient times Hindus belief those rituals & traditions that’s why till now we can’t avoid those things lightly.
Avoid Hair or Nail cutting on certain days is one of the rituals is till practicing by Indians. Elders are suggesting not getting hair or nail cut on Tuesday, Thursday & Saturday. Humans are belief Tuesday, Thursday & Saturday are days of God & Goddess & those practices have positive benefits for humans.