SimpleDateFormat parses wrong date

Question

I'm reading dates with the format "2014-08-01" from a XML file and doing this to convert it to a Date type:

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");
Date eventdate = formatter.parse(date_string_from_xml);

Later I'm using convertDateTime in a JSF file:

<h:outputText value="#{event.date}" ><f:convertDateTime pattern="dd.MM." /></h:outputText></span>

The output is 31.07. and not 01.08. and I don't understand why.