In our shop, we run a nightly cycle to manipulate our data. We have added many new jobs to the nightly job stream; however, not all the jobs are run every night. In an effort to have one main CL program drive all the programs that need to be submitted each night of the week, we have developed the CL program DOW001CL shown in 4 to allow us to determine what day of the week it is on a given day. Before you run this program for the first time, you'll need to create a 20-byte character data area called DAYOFWEEK. When you create this data area, load it with the day of the week in positions 1-10, the Julian date in positions 11-15, and the relative day of the week in position 20. For example, you could use the following command:

In our shop, we run a nightly cycle to manipulate our data. We have added many new jobs to the nightly job stream; however, not all the jobs are run every night. In an effort to have one main CL program drive all the programs that need to be submitted each night of the week, we have developed the CL program DOW001CL shown in Figure 4 to allow us to determine what day of the week it is on a given day. Before you run this program for the first time, you'll need to create a 20-byte character data area called DAYOFWEEK. When you create this data area, load it with the day of the week in positions 1-10, the Julian date in positions 11-15, and the relative day of the week in position 20. For example, you could use the following command:

 CRTDTAARA DTAARA(xxx/DAYOFWEEK) + TYPE(*CHAR) LEN(20) + VALUE('MONDAY 95212 1') 

In this case, we're using Monday, July 31, 1995, as the starting date. Any past date will do as long as the day of the week you pick occurred on the Julian date specified and the relative day of the week (position 20) coincides with the other fields. After you create this data area, you can call the DOW001CL program at the beginning of your nightly job. Then you can retrieve the data from the data area into a variable in your program and use it to determine the day of the week as shown in the example in 5.

In this case, we're using Monday, July 31, 1995, as the starting date. Any past date will do as long as the day of the week you pick occurred on the Julian date specified and the relative day of the week (position 20) coincides with the other fields. After you create this data area, you can call the DOW001CL program at the beginning of your nightly job. Then you can retrieve the data from the data area into a variable in your program and use it to determine the day of the week as shown in the example in Figure 5.

? Neely Loring

TechTalk: Day of Week Calculation

Figure 4: CL Program DOW001CL

 /*===============================================================*/ /* To compile: */ /* */ /* CRTCLPGM PGM(XXX/DOW001CL) SRCFILE(XXX/QCLSRC) */ /* */ /*===============================================================*/ PGM DCL VAR(&JULDAYC) TYPE(*CHAR) LEN(5) DCL VAR(&SYSDATE) TYPE(*CHAR) LEN(6) DCL VAR(&SYSJULDATE) TYPE(*CHAR) LEN(5) DCL VAR(&SYSJULDATC) TYPE(*DEC) LEN(5 0) DCL VAR(&CALCDATE) TYPE(*DEC) LEN(2 0) DCL VAR(&DAYCALCC) TYPE(*CHAR) LEN(1) DCL VAR(&DAYCALC) TYPE(*DEC) LEN(1 0) DCL VAR(&JULDATE) TYPE(*DEC) LEN(5 0) RTVDTAARA DTAARA(DAYOFWEEK (11 5)) RTNVAR(&JULDAYC) RTVSYSVAL SYSVAL(QDATE) RTNVAR(&SYSDATE) RTVDTAARA DTAARA(DAYOFWEEK (20 1)) RTNVAR(&DAYCALCC) CHGVAR VAR(&DAYCALC) VALUE(&DAYCALCC) CHGVAR VAR(&JULDATE) VALUE(&JULDAYC) CVTDAT DATE(&SYSDATE) TOVAR(&SYSJULDATE) + FROMFMT(*MDY) TOFMT(*JUL) TOSEP(*NONE) CHGDTAARA DTAARA(DAYOFWEEK (11 5)) VALUE(&SYSJULDATE) CHGVAR VAR(&SYSJULDATC) VALUE(&SYSJULDATE) CHGVAR VAR(&CALCDATE) VALUE(&SYSJULDATC - &JULDATE) MONMSG MSGID(CPF0000) IF COND(&CALCDATE *EQ 0) THEN(GOTO CMDLBL(ENDPGM)) IF COND(&CALCDATE *NE 0) THEN(DO) CHGVAR VAR(&DAYCALC) VALUE(&CALCDATE + &DAYCALC) MONMSG MSGID(CPF0000) ENDDO IF COND(&DAYCALC *GT 7) THEN(DO) CHGVAR VAR(&DAYCALC) VALUE(&DAYCALC - 7) ENDDO IF COND(&DAYCALC *EQ 1) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('MONDAY') ENDDO IF COND(&DAYCALC *EQ 2) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('TUESDAY') ENDDO IF COND(&DAYCALC *EQ 3) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('WEDNESDAY') ENDDO IF COND(&DAYCALC *EQ 4) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('THURSDAY') ENDDO IF COND(&DAYCALC *EQ 5) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('FRIDAY') ENDDO IF COND(&DAYCALC *EQ 6) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('SATURDAY') ENDDO IF COND(&DAYCALC *EQ 7) THEN(DO) CHGDTAARA DTAARA(DAYOFWEEK (1 10)) VALUE('SUNDAY') ENDDO CHGVAR VAR(&DAYCALCC) VALUE(&DAYCALC) CHGDTAARA DTAARA(DAYOFWEEK (20 1)) VALUE(&DAYCALCC) ENDPGM: ENDPGM 
 
TechTalk: Day of Week Calculation
 
Figure 5: Example CL Program
 
 PGM DCL VAR(&DAYOFWEEK) TYPE(*CHAR) LEN(10) CALL PGM(DOW001CL) RTVDTAARA DTAARA(DAYOFWEEK (1 10)) RTNVAR(&DAYOFWEEK) IF COND(&DAYOFWEEK *EQ 'MONDAY') THEN(DO) . . . ENDDO IF COND(&DAYOFWEEK *EQ 'TUESDAY') THEN(DO) . . . ENDDO ENDPGM