When you create a todo, the todo will be either undated, dated with today's date, or dated with another date. Here is how to control which happens:
If you chose to display undated todos, Datebk will add new todos without a date. If you hide undated todos, Datebk will default to today's date.
In the todos preferences, check the setting of the check box "Hide Undated todos". This page has not yet been updated for Datebk6, in which hiding undated todos is done differently.