Settings : Today Widget & Apple Watch
Today Widget and Apple Watch follows one of your list settings. You can pick one list for each and choose one from (List/Day/Week/Month). Tasks that belong to that view will be shown on Today Widget and Apple Watch.
For example, if you have a list with calendar events, calendar events will also be shown on Widget. If you have set it to (List), you'll see all the tasks without limits to due dates.