What does "five-thirty" mean in English for Spanish?

In English for Spanish, "five-thirty" means:

5:30

Listen to "five-thirty": (If you have an HTML5 enabled browser, you can listen to the native audio below)

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

• English for Spanish 3, Level 2, Scene 11
• English for Spanish 3, Level 3, Scene 1