usually, the Password-Interval filed is set according the shops requirement, you can set this globally for all users by issuing the following caommand:
SETR PASSWORD(INTERVAL(30))
Then you need to issue the refresh command. For a single user you can issue the following command:
PW INTERVAL(30) USER(USER-ID)
There's no need to issue a refresh command when used for a single user.
This command can be invoked from option-6 TSO commands.