using AIF services to query data

Hi,
I am using the following code to query Purchase Orders from AX 2012 R2.

string time = "12/7/2008 08:32:51";
QueryCriteria qc = new QueryCriteria();
CriteriaElement ce = new CriteriaElement();
ce.DataSourceName = "PurchTable";
ce.FieldName = "modifiedDateTime";
ce.Operator = Operator.Equal;
ce.Value1 = time;
CriteriaElement[] cce = new CriteriaElement[1];

cce[0] = ce;
qc.CriteriaElement = cce;
PO = svcClient.find(callContext, qc);

but i am geting the error UTC date\time string is not in the expected format. have anyone tried this and can tell me the correct format?

i can fetch data using other fields but i want to use the modified date time field.

Please Help

Thanks