Вот какая крутотень:
type Day_type is range 1 .. 31;
type Month_type is range 1 .. 12;
type Year_type is range 1800 .. 2100;
type Hours is mod 24;
type Weekday is (Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday);
type Date is
record
Day : Day_type;
Month : Month_type;
Year : Year_type;
end record;