No Such Thing

It has to be intriguing to the aliens. 

"Hey Bob, watch this!"

"What's up?"

"These primitive things created a strictly regimented structure called Time. Fairly intelligent, I'll give them that...but twice a year, some of them literally, in a ritual like manner, EAT AN HOUR, and throw it back up 6 months later."

But they don't believe in magic.

They call it "science" here. 

Just keep an eye on them.