I used to be using both start date and due date, setting both to the same date, so this task will not show up normally, lately I was thinking whether I can use just the Due On instead, since according to the description, Due On is for tasks that I don't want to be reminded about, which for me is the same with Start Date.
Is there a specific reason why Due On will still appear if the task is within 7 days in the future even though I have "Show Future Tasks" as off? I would have expected it to behave like Start Date.
There is a slight difference between start-date and due-on. The due-on date will show for the week leading up to it so that you can be reminded of the event. If you don't want to see it until the day of, use a start-date.
Maybe you can just update the help text which reads:
Sometimes a task can only be completed on a specific due date (like a dentist appointment) and being reminded about it ahead of time is unnecessary. You can fix this by setting it to be due "on" the date. The abbreviation for this is an equals sign in front of the date. For example "=2008-01-01". This signifies that this task can only be completed on Jan 1, 2008 and that we shouldn't worry about it until then.
The description sound really a lot like start dates, and there's no reference to this 1 week reminder.