seperate date & time on traffic graphs

Fixes text overflowing and looks nicer ;)

![original](https://f.cloud.github.com/assets/4223752/875147/ae6af6b4-f89a-11e2-8c09-21bbfda1909e.png)
![separate](https://f.cloud.github.com/assets/4223752/875148/b1c9e072-f89a-11e2-915f-99e4a5330139.png)