This method generates a sequence of the contained
DayNotes instances. It takes no arguments. The
generated instances may not be in any predictable order.
See Section 9, “
class DayNotes: Notes for one day”.
There may be multiple
for the same date and state. For example, when
performing censuses such as the Christmas Bird Count and
North American Migration Count, the author prefers to
keep census records in one
element, separating into another
element casual observations not made within the census