BTW, this is UniVerse on AIX 7.2

Nelson,

I used the program below to do some testing on an internal systems running UV 11.3.5 on AIX 7.1

The customer file before I did anything

# ls -al CUSTOMER.F
-rw-r--r--    1 root     system         5120 Jul 29 2021  CUSTOMER.F

001: OPEN "CUSTOMER.F" TO F.FILE ELSE STOP
002: STATUS FILE.STATUS FROM F.FILE ELSE STOP
003: CRT "Time Now " : OCONV(TIME(),"MTS")
004: CRT "Date Now " : OCONV(DATE(),"D4/")
005: CRT
006: CRT "Time of Last Access " : OCONV(FILE.STATUS<13>,"MTS")
007: CRT "Date of Last Access " : OCONV(FILE.STATUS<14>,"D4/")
008: CRT "Time of Last Modification " : OCONV(FILE.STATUS<15>,"MTS")
009: CRT "Date of Last Modification " : OCONV(FILE.STATUS<16>,"D4/")
010: CRT "Time of Last Status Change " : OCONV(FILE.STATUS<17>,"MTS")
011: CRT "Date of Last Status Change " : OCONV(FILE.STATUS<18>,"D4/")
012: END

Time Now 04:22:30
Date Now 13/06/2023

Time of Last Access 04:22:30
Date of Last Access 13/06/2023
Time of Last Modification 05:59:15
Date of Last Modification 29/07/2021
Time of Last Status Change 11:49:04
Date of Last Status Change 19/08/2022

In terms of the last access pair file systems can be mounted with "noatime" or "nodiratime" and stops the recording of the access times on files and directories. It is often used as a performance gain so I suspect the file system your files reside on may have been mounted with these options. You need to check to see with which options the file system was mounted with as this would explain why the last access time is not working for you.

I then did a chmod 666 and reran the program

# chmod 666 CUSTOMER.F
# ls -al CUSTOMER.F
-rw-rw-rw-    1 root     system         5120 Jul 29 2021  CUSTOMER.F

Time Now 04:31:00
Date Now 13/06/2023

Time of Last Access 04:31:00
Date of Last Access 13/06/2023
Time of Last Modification 05:59:15
Date of Last Modification 29/07/2021
Time of Last Status Change 04:29:55
Date of Last Status Change 13/06/2023

So based on my testing, the date and time of last access do work as long as the os has the faciltiy enabled.
The Last Modification Pair seem to be the creation date / time.
The Status change pair are when something about the file at the os level changes such as doing a chmod etc. I suspect there are other commands that impact the status change as well but chmod is a simple one to test.

I hope this explains them a little bit more.

Regards,