Diagnosis
When the data of a work item is changed, only dates/times in the futurecan be specified.
In the future means the specified date is either later than the systemdate or if the date is the same the specified time is one delta laterthan the system time.
This delta in seconds is defined in the workflow system.

System Response
The specified data is not transferred, that is, the deadline data ofthe work item is not changed.

Procedure
Enter a later date / time.