Due date leads the When sheet

The ordinary choice comes first

When now opens on Due date for a task with no timing set. Setting a deadline is the common path, while Later remains available when you intentionally want to remove a task from active lists.

Your existing timing still leads

Tasks already set for Later, Waiting, or Someday reopen on Later. Existing reminders reopen on Remind, and existing deadlines reopen on Due date.

Opening never changes the task

Tomorrow can appear as a helpful starting value, but Apply stays disabled until you explicitly choose a date. Cancel clears every staged choice.