use of tiempo

Question

In Spanish, to talk about how many times someone does something we use the word "vez" (not "tiempo").When is tiempo used?

Answer

Hola Goo
"Tiempo" is a noun meaning "time" and also "weather" but to express how many times one does something or something happens, as explained in the lesson, we use vez/veces. 
Here are some sentences using the word "tiempo":

¿Qué tiempo hace hoy en tu ciudad?
What's the weather like in your city today?
Estás tardando mucho tiempo en el baño.
You're taking too long [a lot of time] in the bathroom.
En tiempos de Franco todo era muy diferente.
In Franco's times everything was different.

You can also see here the different contexts where you can use "tiempo" in Spanish:
wordreference: tiempo 
Saludos cordiales
Inma