図５

Figure 5 - Using free-format date functions


*.. 1 ...+... 2 ...+... 3 ...+... 4 ...+... 5 ...+... 6 ...+... 7 ...+... 8
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H NoMain
* ------------------------------------------------------------- Prototypes
D DayOfWeek        PR        5I 0
D                                  D    Value

D WeekOfYear        PR        5I 0
D                                    D    Value

* ------------------------------------------------------------------------
*
*Procedure: DayOfWeek
*Description: Retrieve day of week using ISO 8601 standard
*               (0=Monday ﾉ 6=Sunday)
*
P DayOfWeek      B              Export

D DayOfWeek      PI      5I 0
D DateIn                      D    Value

D NbrDays        S        10I 0

D Monday        C              D('2001-01-04')

  /Free

    NbrDays = %DIFF(DateIn:Monday:*DAYS);
    Return = %REM( %REM(NbrDays:7) + 7 : 7);

  /End-Free

P DayOfWeek E
*------------------------------------------------------------------------
*
*Procedure: WeekOfYear
*Description: Retrieve week of year using ISO 8601 standard
*          (Year starts on Monday of week containing January 4)
*

P WeekOfYear        B            Export

D WeekOfYear        PI        5I 0
D DateIn                            D    Value

D        DS
D Jan04Date                      D    INZ(D'0001-01-04')
D Jan04Year                    4    0 Overlay(Jan04)

D FirstMonday            S      D
D Jan04DOW          S          5I 0

  /Free

    // Change Jan04Date to target year,
    // then calculate first Monday of target year
    Jan04Year = %SUBDT(DateIn:*Y);
    Jan04DOW = DayOfWeek(Jan04Date);
    FirstMonday = Jan04Date - %DAYS(Jan04DOW);

    // If target date is before first Monday, switch to prior year
    If DateIn < FirstMonday;
      Jan04Year = Jan04Year ﾐ 1;
      Jan04DOW = DayOfWeek(Jan04Date);
      FirstMonday = Jan04Date - %DAYS(Jan04DOW);
    Endif;

    // Return week number (number of full weeks since first Monday + 1)
    Return %DIV(%DIFF(DateIn:FirstMonday:*DAYS):7) + 1;

  /End-Free

P WeekOfYear    E