ParseException using Exprssion in DateFormField

Hi all,

im using the following expression as an default value in an UserTask FormField of type Date. The Funny Thing is that the Value i want is a value of another UserTask FormField of type… you guess… Date. I´m wondering that this throws an exeption.

The expression is: ${startDate}, startDate = the Variablekey

Could anybody tell me how to fix this if i want just the date without the time like 2018-01-01 instead of “Sat Jun 09 00:00:00 CEST 2018” and what the exception is exactly about? I know there are some very simmilar topics on the forum but i´m not satisfied with thissolutions since they are talking about the parsing to a dateTime.

Here´s the important part of the stacktrace:

Caused by: org.camunda.bpm.engine.ProcessEngineException: invalid date value Sat Jun 09 00:00:00 CEST 2018
    at org.camunda.bpm.engine.impl.form.type.DateFormType.convertFormValueToModelValue(DateFormType.java:97)