An instance of this class is a container for all the notes for one day within one state.
BirdNoteSet instance that
contains this instance.
The lowercased postal code, e.g.,
for New Mexico.
The date as a string, formatted as
DaySummary instance representing the
day's general features. See Section 10, “
class DaySummary: Daily context”.
A locality that includes all the day's notes, as a
Loc instance. See Section 11, “
class Loc: Locality code definition”.