Yosef - Since you have an R1.1, you can only set the number of rings before the Auto Attendant answers to either Immediate Answer (which is 2 rings) or Delayed Answer (which is 4 rings). This affects both Day and Night Mode.
If you set it to Immediate Answer, and set the phones to either Delayed Ring (4-rings) or No Ring, then NO phones will ring on the initial ring-in. After the Automated Attendant answers, and transfers the call, it will ring at the intended station.
For Sabbath Mode, put a DND button on each phone, and instead of ringing, the call will go directly to the station's voice mailbox.
If you purchased your Partner from an Avaya Business Partner dealer, they may be willing to upgrade you to a newer release for no or a small charge. Business Partners can now download and reprogram the flash card from your system to upgrade the software. By going to at least a release 3 (current release is 4) you can change the number of rings before the Auto Attendant answers on a per-line basis, day-night basis, from 0 to 9 rings.