Specifies the formatting pattern used to show the time and/or date in 24-hour mode. Please refer to Android.Text.Format.DateFormat for a complete description of accepted formatting patterns. The default pattern is a locale-appropriate equivalent of "H:mm".

Must be a string value, using '\\;' to escape characters such as '\\n' or '\\uxxxx' for a unicode character.

This may also be a reference to a resource (in the form "@[package:]type:name") or theme attribute (in the form "?[package:][type:]name") containing a value of this type.

[Android Documentation]