Don't add time to date value

Normally, when creating a Date object, your browser will add a time taking into account your time zone:
```
new Date("2014-08-13")
Wed Aug 13 2014 02:00:00 GMT+0200 (CEST)
```
When you add a specific time yourself, you lose this behavior:
```
new Date("2014-08-13 00:00")
Wed Aug 13 2014 00:00:00 GMT+0200 (CEST)
```
As a result, the database could show incorrect date values as they're converted to UTC:
```
2014-08-12 22:00:00.000Z
```