Due date of the task (as a RFC 3339 timestamp). Optional. The due date
only records date information; the time portion of the timestamp is
discarded when setting the due date. It isn't possible to read or write
the time that a task is due via the API.
String indicating the position of the task among its sibling tasks under
the same parent task or at the top level. If this string is greater than
another task's corresponding position string according to lexicographical
ordering, the task is positioned after the other task under the same
parent task (or at the top level). This field is read-only. Use the "move"
method to move the task to another position.