By design, DevTest use the Magic Date functions doDateDeltaFromCurrent() and doDateDeltaFromRequest() when magic string the dates in Request and Response. Here is how the VSI->Response is created with the date functions.
. doDateDeltaFromCurrent() - When there is no date in the request but the response has a date then VSI creates a magic date using doDateDeltaFromCurrent.
. doDateDeltaFromRequest() - When a Date is in the Request and the same Date is also in the Response then VSI creates a magic date using doDateDeltaFromRequest.