!! File Time.ili Release 2017-04-12

INTERLIS 2.2;

!! 2017-04-12 Mandatory constraint adapted (line 59)
!!@precursorVersion = 2003-03-18

REFSYSTEM MODEL Time (en) =  !! en = 2-letter code (ISO 639)

  CONTRACT ISSUED BY Unknown;  !! Contractor(s) have to be defined!

  IMPORTS Units;

  UNIT
    HM = {Units.h : Units.min[0 .. 59]} CONTINUOUS;
    HMS = {Units.h : Units.min[0 .. 59] : INTERLIS.s[0 .. 59]} CONTINUOUS;

    Year [Y] EXTENDS INTERLIS.TIME;
    Month [M] EXTENDS INTERLIS.TIME;

    DayOfYear [MD] = {M:Units.d[1 .. 31]};
    Date [YMD] = {Y:M[1 .. 12]:Units.d[1 .. 31]};

  DOMAIN
    Year = 1582 .. 2999 [Y]; !! Gregorian Calendar
    Date = 1582:10:15 .. 2999:12:31 [YMD];
    DayOfYear = 1:1 .. 12:31 [MD];

    WeekDay = (WorkingDay (Monday, Tuesday, Wednesday,
               Thursday, Friday, Saturday), Sunday);

    HMOfDay = 0:0 .. 23:59 [HM];
    DifferenceToUTC = MANDATORY -13:00 .. 13:00 [HM]; !! UTC := LocTime + Diff

  FUNCTION AppropriateDate (dayOfYear: MANDATORY DayOfYear;
                            weekDay: WeekDay): DayOfYear
    // returns first parameter if second is undefined
       returns first day from (incl) first parameter being the
       requested weekday //;

  FUNCTION DSTOrdered (day1: DayOfYear; day2: DayOfYear) : BOOLEAN
    // returns TRUE if the second parameter comes after the
       first parameter or if both parameters are equal //;

  STRUCTURE DSTransition =
    TransitionDSTime: MANDATORY HMOfDay;
    FirstDate: MANDATORY DayOfYear;
    DayOfWeek: WeekDay;
    TransitionDate: DayOfYear := AppropriateDate (FirstDate, DayOfWeek);
  END DSTransition;

  STRUCTURE DaylightSavingPeriod =
    DSToUTC: DifferenceToUTC;
    From: MANDATORY Year;
    To:   MANDATORY Year;
    DSStart: MANDATORY DSTransition;
    DSEnd: MANDATORY DSTransition;
  MANDATORY CONSTRAINT
    DSTOrdered (DSStart->FirstDate, DSEnd->FirstDate);
  MANDATORY CONSTRAINT
    To >= From;
  END DaylightSavingPeriod;

  FUNCTION DSPOverlaps (periods: BAG {1..*} OF DaylightSavingPeriod) : BOOLEAN
    // returns TRUE if any one of the periods overlap //;


  TOPIC TimeZone =

    CLASS TimeZone (ABSTRACT) EXTENDS INTERLIS.SCALSYSTEM =
    PARAMETER
      Unit (EXTENDED): NUMERIC [INTERLIS.TIME];
    END TimeZone;

    CLASS BaseTimeZone EXTENDS TimeZone = !! TimeZone without daylight saving
      DiffToUTC: DifferenceToUTC;
    END BaseTimeZone;

    CLASS DaylightSavingTZ EXTENDS TimeZone =
      Periods: BAG {1..*} OF DaylightSavingPeriod;
    MANDATORY CONSTRAINT
      NOT ( DSPOverlaps (Periods) );
    END DaylightSavingTZ;

    ASSOCIATION DaylightSavingTZOf =
      BaseTZ -<> BaseTimeZone;
      DSTZ -- DaylightSavingTZ;
    END DaylightSavingTZOf;

  END TimeZone;

END Time.