When do shops close in Cozumel?

[peachyisthelife]

We'll be in port from 11am to 8pm. We'd like to do our Mr Sanchos thing first thing since they close at 5 I think. But I was worried that shops in Coz closed early and we wouldn't be able to hit many, if any, of them after we leave the beach. Are they open after 5? What time do a lot of them close? Seems like I heard somewhere that some stores take a siesta in the afternoon, true? Common? Thanks for any help ya got!