codice:
Set a minimum selectable date via a Date object or as a string in the current dateFormat, or a number of days from today (e.g. +7) or a string of values and periods ('y' for years, 'm' for months, 'w' for weeks, 'd' for days, e.g. '-1y -1m'), or null for no limit.

Code examples
Initialize a datepicker with the minDate option specified. 
$( ".selector" ).datepicker({ minDate: new Date(2007, 1 - 1, 1) });Get or set the minDate option, after init. 
//getter
var minDate = $( ".selector" ).datepicker( "option", "minDate" );
//setter
$( ".selector" ).datepicker( "option", "minDate", new Date(2007, 1 - 1, 1) );