Fix graphical glitch when opening date fields in landscape

Before
![screen shot 2014-12-09 at 23 05 02](https://cloud.githubusercontent.com/assets/57446/5366913/e58dc1d6-7ff7-11e4-8d5f-6c8fb0e516a0.PNG)

After
![screen shot 2014-12-09 at 23 03 18](https://cloud.githubusercontent.com/assets/57446/5366917/eb5fd2b6-7ff7-11e4-8ea1-40c0f459ae07.PNG)