Default:'mm/dd/yy'
The format for parsed and displayed dates. This attribute is one of the regionalisation attributes. For a full list of the possible formats see the formatDate function.

Code examples

Initialize a datepicker with the dateFormat option specified.
$( ".selector" ).datepicker({ dateFormat: 'yy-mm-dd' });
Get or set the dateFormat option, after init.
//getter
var dateFormat = $( ".selector" ).datepicker( "option", "dateFormat" );
//setter
$( ".selector" ).datepicker( "option", "dateFormat", 'yy-mm-dd' );