Store Hours

I have a small shop.

Here is a conversation in said shop:

GUY: "Finally! You're open!"

ME: "What do you mean?"

GUY: "You're always closed when I come down."

ME: "You should probably come down when I'm open."

GUY: "You're never open."

ME: "Actually I've been open every day for thirty years except for Christmas and Thanksgiving."

GUY: "Not when I come down."

ME: "You should come down during our store hours."

GUY: "What are those?"

ME: "The hours when you don't come down."