-- Describes each term time.
-- TermIdentifier is either W for Winterterm or S for Summerterm,
-- followed by a two-digit year
Term json
    name          TermIdentifier -- unTermKey :: TermId -> TermIdentifier
    start         Day            -- TermKey   :: TermIdentifier -> TermId
    end           Day
    holidays      [Day]          -- LMU holidays, for display in timetables
    lectureStart  Day            -- lectures usually start/end  later/earlier than the actual term,
    lectureEnd    Day            -- used to generate warnings for lecturers creating unusual courses
    active        Bool           -- may lecturers add courses to this term?
    Primary name       -- newtype Key Term = TermKey { unTermKey :: TermIdentifier }
    deriving Show Eq Generic -- type TermId = Key Term