Reproduce:

• add a variable of type date to a process instance (e.g. name = "date" value = "2014-04-14T10:27:51")
• go to process definition view in cockpit
• filter by variable using: date = "2014-04-14T10:27:51"

Problem:

• process instance is not found

Expected:

• the process instance with this variable should appear in list on process definition view

Hint: probably the filter mechanism does not realize that this is a date and executes a like query as with any other string