I set the GridColumn DisplayFormat="{0: yyyy-MM-dd}" and the data reflects that format. The default filter control doesn't. How can I make the control do that?
---
ADMIN EDIT
For the time being, the way to affect the filter behavior is through a custom filter template. The format for date pickers and numeric textboxes comes from the app culture settings (see more here). You may also want to Follow this idea for easier selection of a default filter operator and limiting the filter operators choices.
---