How to compute custom timestamp in COBOL85 Tandem?

I want to calculate timestamp for custom date and time. E.g 23/09/2022 4:30:45

Solution

To calculate Julian Timestamp of current date and time you can use JULIANTIMESTAMP using ENTER TAL but for Custom timestamp we have COMPUTETIMESTAMP GPC .

Syntax from GPC Reference manual

jval := COMPUTETIMESTAMP ( date-n-time,
                           [error-mask] );

Data types

jval is 64-bit Fixed Julian timestamp .

date-n-time is an integer array of date and time [YYYY,MM,DD,HH,,MM,SS,MIL,MIC] all elements of array are compulsory.

error-mask is integer array of bits 1 or 0 of length 8.

So let's Jump to the main Question how to Calculate Custom timestamp in COBOL85 . I have small example .

?ANSI
 ?save param
 ?symbols
 ?inspect
         IDENTIFICATION DIVISION.
             PROGRAM-ID. HELLO.

         ENVIRONMENT DIVISION.

         DATA DIVISION.
             WORKING-STORAGE SECTION.
                 01 USER-FLD-CUST  PIC X(50).
                 01 ARR.
                    03 DT          PIC S9(4) COMP OCCURS 8 TIMES.
                 01 VAL            PIC 9(16).
                 01 JTIME          PIC S9(18) VALUE 0.
                 01 CER.
                    03 ERR         PIC S9(1) COMP OCCURS 8 TIMES.


         PROCEDURE DIVISION.
             PROGRAM-BEGIN.
             MOVE 2022 TO DT(1).
             MOVE 99   TO DT(2).
             MOVE 30   TO DT(3).
             MOVE 10   TO DT(4).
             MOVE 00   TO DT(5).
             MOVE 00   TO DT(6).
             MOVE 000  TO DT(7).
             MOVE 000  TO DT(8).

             ENTER TAL "COMPUTETIMESTAMP" USING ARR , CER
                        GIVING JTIME.
             IF JTIME = -1
                 DISPLAY "INVALID DATE"
             ELSE
                 DISPLAY JTIME.
             STOP RUN.