var TodayDesde = new Date;

setTimeout("initDateRange()", 1000);

function initDateRange() {
	if ( document.getElementById('date1') )
	{
		Calendar.setup({
			inputField     :    "date1",   // id of the input field
			ifFormat       :    "%d/%m/%Y",       // format of the input field
			showsTime      :    false,
			timeFormat     :    "24",
			button         :    "popupcal",
			range	       :    [TodayDesde.getFullYear(), TodayDesde.getFullYear()+1],
			weekNumbers    :    false,
			dateStatusFunc :    dateStatusHandlerFrom,
			onUpdate       :    updateTo
		});

		Calendar.setup({
			inputField     :    "date2",   // id of the input field
			ifFormat       :    "%d/%m/%Y",       // format of the input field
			showsTime      :    false,
			timeFormat     :    "24",
			button         :    "popupcal2",
			range	       :    [TodayDesde.getFullYear(), TodayDesde.getFullYear()+1],
			weekNumbers    :    false,
			dateStatusFunc :    dateStatusHandlerTo
		});

		document.getElementById('date1').onclick = document.getElementById('popupcal').onclick;
		document.getElementById('date2').onclick = document.getElementById('popupcal2').onclick;
	}
}

function dateStatusHandlerFrom( date, y,m,d ) {
	var x = document.getElementById('date2');
	var today = new Date(2012,1,5,0,0,0);
	if ( !x.value )
	{
		return date < today;
	}
	date2 = x.value.split('/');
	var to = new Date( parseInt( date2[2], 10 ), parseInt( date2[1], 10 )-1, parseInt( date2[0], 10 ), 0,0,0 );
	to.setDate( to.getDate() + 1 );
<!-- 	return ( date < today || date >= to );  -->
	return ( date < today );
}
function dateStatusHandlerTo( date, y,m,d ) {
	var x = document.getElementById('date1');
	var tomorrow = new Date(6,1,2012,0,0,0);
	if ( !x.value )
	{
		return date < tomorrow;
	}
	date1 = x.value.split('/');
	var from = new Date( parseInt( date1[2], 10 ), parseInt( date1[1], 10 ) - 1, parseInt( date1[0], 10 ) );
<!-- 	return ( date <= from ); -->
	return false;
}
function updateTo() {
	if ( !document.getElementById('date2').value )
	{
		var raw = document.getElementById('date1').value;
		var date1 = raw.split('/');

		var x = new Date( parseInt( date1[2], 10 ), parseInt( date1[1], 10 )-1, parseInt( date1[0], 10 ), 0,0,0 );
		x.setDate( x.getDate() + 1 );
		document.getElementById('date2').value = x.getDate() + '/' + ( x.getMonth() + 1 ) + '/' + x.getFullYear();
	}
}