Just when i think im done...

This happened only a couple weeks ago, in IT we recently did audio podcasts on garage band. I chose top 10 cars and made my podcast. I was pretty happy, my podcast was working out great almost done just finishing up the last 2 and then this girl in my class came by...lets call her penuts. So penuts was looking at my podcast and was saying that mine was to long. I didn't understand because i thought my timer said it was in seconds and we could have a maximum of like 5 minutes or something. Mine said it was like 300 "seconds" and she walks around and says "No, your in tempo," click, "now your in time." So i check how long it is and it turns out its 12 minutes! I thought i was close, and failed =(