Fix not displaying day on commits history

Attention:
This problem is not occured on development mode.
I have tested by chrome.

Before:
![fix_display_day_before](https://f.cloud.github.com/assets/72138/92614/909277d2-65e4-11e2-9557-036caeea983a.png)

After:
![fix_display_day_after](https://f.cloud.github.com/assets/72138/92617/9bd890f4-65e4-11e2-8807-3dd00b2ee108.png)