Reproducing Date serialization issue - VF page

gistfile1.html

<apex:page controller="DateIssueRepro">
<!-- Simple VF page to demonstrate issue with setting Date fields of SObjects via Remoting -->
<!-- This is case 08471144 -->
<!-- Author: Jeff Trull <jetrull@sbcglobal.net> 2012-12-09 -->
<apex:form >
	<table>
		<tr>
			<th>Date source</th>
			<th>New value</th>
		</tr>
		<tr>
			<td><apex:outputLabel value="SObject field" for="sobjdate"/></td>
			<td><apex:inputText id="sobjnewvalue"/></td>
			<td><input type="button" value="Submit"
				onclick="setDate('{!$Component.sobjnewvalue}','{!$Component.sermethod}')"/> </td>
		</tr>
		<tr>
			<td><apex:outputLabel value="Date" for="regulardate"/></td>
			<td><apex:inputText id="regularnewvalue"/></td>
			<td><input type="button" value="Submit"
				onclick="setDate('{!$Component.regularnewvalue}','{!$Component.sermethod}')"/></td>
		</tr>
	</table>
	<apex:outputLabel value="Serialization Method:" for="sermethod" style="font-weight: bold"/>
	<apex:selectRadio id="sermethod" value="{!selectedSer}">
		<apex:selectOption itemValue="none" itemLabel="None"/>
		<apex:selectOption itemValue="epoch" itemLabel="Seconds since Epoch"/>
		<apex:selectOption itemValue="date" itemLabel="Javascript Date"/>
		<apex:selectOption itemValue="utc" itemLabel="UTC String"/>
	</apex:selectRadio>
</apex:form>

<script>
function setDate(inputid, methodid) {
	var datestr = document.getElementById(inputid).value;
	// find desired method from radio buttons
	var methodels = document.getElementsByName(methodid);
	var method;
	for (var i = 0; i < methodels.length; i++) {
		if (methodels[i].checked) {
			method = methodels[i].value;
		}
	}	
	console.log('using method "' + method + '" to process "' + datestr + '"');
	var serializedDate;
	if (method == 'none') {
		// just send it directly
		serializedDate = datestr;
	} else if (method == 'epoch') {
		serializedDate = new Date(datestr).getTime();     // works for Date field inside sObject (as of Spring 13)
	} else if (method == 'date') {
		serializedDate = new Date(datestr);
	} else if (method == 'utc') {
		serializedDate = new Date(datestr).toUTCString(); // works for plain Date values
	} else {
		console.log('unknown serialization method:', method);
		return;
	}
	console.log('serialized data is:', serializedDate);
	// launch to appropriate remote method
	if (endsWith(inputid, 'regularnewvalue')) {
		DateIssueRepro.updateDate(serializedDate,
								  function(response, e) {
								  	if (!e.status) {
								  		console.log('call failed with status', e.message);
								  	} else {
								  		console.log('call succeeded');
								  	}});
	}
	if (endsWith(inputid, 'sobjnewvalue')) {
		DateIssueRepro.updateContact({Birthdate: serializedDate},
								  function(response, e) {
								  	if (!e.status) {
								  		console.log('call failed with status', e.message);
								  	} else {
								  		console.log('call succeeded');
								  	}});
	}
}
	
// utility function.  Thanks, Stack Overflow:
function endsWith(str, suffix) {
    return str.indexOf(suffix, str.length - suffix.length) !== -1;
}

</script>


</apex:page>