here in good old england cumbria were free from anyhting like that no rules except laws of course were pretty boring really
Yes, a common superstition here is: You can't eat clams on the months without the "R" word on the name. Example: June, July or August. The people says: "If you eat a clam on this time (August example) you will have bad luck the next 6 months". And is real, anyone eat's clam on this season. I eat clams and don't have bad luck. But is a supertition anyway.
"Knowledge is power"