What does "On Sunday things are pretty quiet." mean in English for Spanish?

In English for Spanish, "On Sunday things are pretty quiet." means:

Los domingos están las cosas bastante tranquilas.

Listen to "On Sunday things are pretty quiet.": (If you have an HTML5 enabled browser, you can listen to the native audio below)

This is a phrase that is used in the GamesForLanguage English for Spanish Language Game in the following scenes:

• English for Spanish 4, Level 3, Scene 3