The date format string used by the receiver.
- iOS 2.0+
- macOS 10.0+
- tvOS 9.0+
- watchOS 2.0+
See Data Formatting Guide for a list of the conversion specifiers permitted in date format strings.
You should only set this property when working with fixed format representations, as discussed in Working With Fixed Format Date Representations. For user-visible representations, you should use the
time properties, or the
set method if your desired format cannot be achieved using the predefined styles; both of these properties and this method provide a localized date representation appropriate for display to the user.