The options are these three formats:
dd.MMM.yyyy (MMM like Jul, Aug, …)
MM/dd/yyyy (US)
yyyy-MM-dd (ISO8601)
To work with date and time in KNIME I suggest that you keep the standard format in ISO8601 and when you want to export the table elsewhere in your desired format (dd-MM-yyyy) then change the format. That would be easy to be done in a String Manipulation node with this expression:
join(substr($column1$, 8,2), "-", substr($column1$, 5,2), "-", substr($column1$, 0,4))
Where “column1” is your date column.
This will change 2018-12-01 to 01-12-2018
Armin