So you were using a child relationshiop field.
There is a known bug where child relationship fields are not formatted correctly when you follow the canonical process for including child relationship fields in a table or field editor:
1. Select child object to include in model. (Object now appears in left hand panel field list)
2. Click on object in field list to define fields and filters.
3. Drag object from field list into the component. It appears as a template where fields selected can be defined using merge syntax.
When this mechanism is used - field renderers are not run and raw data is included in the page. Rather than 7/03/2014 4:38 pm we get 2014-10-14T05:12:42.000+0000
There is however a workaround: Drag a template component from the component list into the table or field editor and use the following syntax:
This will show the field with correct formatting.