A date time format is a format for displaying Date or DateTime components in grids and forms. A default format can be set in System Configuration and in each application. Individual components can have a date time format set in stream view attribute for grids or layout component for forms. 

Date Time Format Properties

Basic Settings

Date Style Mapping 

This section has a toolbar with standard buttons.

The grid contains a list of mappings from this date/time to specific date styles. To add a mapping to the list, click  Add. PhixFlow opens a new date style mapping properties tab; see Date Style Mapping for details.

To remove a mapping from the list, use the toolbar button  Permanently Delete.