Since the Due Date field is what controls most things this field have to be used if you want to work with dates. We run marketing campaigns and we usually set things as a start date and end date.
What bothers us is that the field especially in Swedish is labeled as Due Date (SE: Slutdatum) when it in fact should only be “Dates” or “Time frame” or “Time period” or just being free to rename to whatever you like.
This only has to be a visual change and not a hard change in the code or the function of the due date field.
Also when you create a new task and select date the “Start date” field is really quite hidden or hard to see, making these date selections as more clear buttons would be recommended.