BBC IA: Fix bad string ification of times

Here's what the problematic time stringification looks like:
![Bad time string](https://f.cloud.github.com/assets/2399307/2430905/cdfaa53a-ad0b-11e3-892e-d8de361e1f86.png)
It seems to double the minutes when they're over 9 and turn 12 AM into 1 AM and 12 PM into 1 PM. Here's what the same guide looks like in this updated version:
![Good time string](https://f.cloud.github.com/assets/2399307/2430936/f80ce318-ad0d-11e3-8716-7a4c5b91143e.png)
I've changed it to show midnight as 0 AM (this can be changed easily) and to keep the minutes and hours unmodified.