Look at system value QINACTITV. Just be aware that this will affect all users.
I would stay away from the inactivity time out because it DOES effect everyone.
IBM gives you a nice tool that may be what you want.
GO SECTOOLS – Look at the option for “Change Activation Schedule Entry” (You’ll need *SECADM authority for this.
You can set the Time to enable and disable specific users, and additionally what days (day of the week) to do this on.
I don’t know if this will kick the user off if they are signed on and the “deactivation” time comes up, but it will prevent them from signing on.
Mike is correct, however if you are are looking for a global setting. You could user the INACTIVITY timer, but add it to a scheduler and therefore you can turn on/of at will, we actually durn it on at the end of the 1st shift
example: at 4pm CHGSYSVAL SYSVAL(QINACTITV) VALUE(’20′)
We also enable: QDSCJOBITV 10 – This will disconnect but not end their job, in case they are still actually working.