It sounds, from your description, that your dad is growing Datura aka moonflower.

OP said "produces seed pods and seeds like a hibiscus" which would rule out Datura. I'm also curious about the remark that " It opens up late in the day." Without a picture of the flower and foliage, it's just a guessing game.

Do a Google Images search for "white hibiscus" and maybe you can spot it.