If you want to know last IPL date.
You can run this command on green screen
WRKJOB JOB(000000/*N/SCPF)and then use option
1. Display job status attributes Started is section where you will find answer
Display Job Status Attributes
System: IBMS
Job: SCPF User: QSYS Number: 000000
Status of job . . . . . . . . . . . . . . . : ACTIVE
Current user profile . . . . . . . . . . . : QSYS
Job user identity . . . . . . . . . . . . . : QSYS
Set by . . . . . . . . . . . . . . . . . : *DEFAULT
Entered system:
Date . . . . . . . . . . . . . . . . . . : 12/11/23
Time . . . . . . . . . . . . . . . . . . : 09:42:11
Started:
Date . . . . . . . . . . . . . . . . . . : 12/11/23
Time . . . . . . . . . . . . . . . . . . : 09:42:11
Subsystem . . . . . . . . . . . . . . . . . :
Subsystem pool ID . . . . . . . . . . . . :
Type of job . . . . . . . . . . . . . . . . : SYS
Special environment . . . . . . . . . . . . : *NONE
Program return code . . . . . . . . . . . . : 0
Another way is to use SQL command
SELECT MESSAGE_TIMESTAMP
FROM TABLE(QSYS2.JOBLOG_INFO('000000/QSYS/SCPF'))
LIMIT 1