I have a 4-line phone, an AT&T 954. I'm looking for an on-line manual
(or equivalent resource) for the phone so I can set time & date,
program in phone numbers, etc.

Hello, and thank you for using Google Answers for your question!
AT&T does not have the manual online for your phone, and the two
closest model numbers are both bad links. However, I did find the
manual here, for $5.50 plus shipping.

Owner's Manuals
http://ownmanual.tripod.com/inventory-office.htm
Scroll down until you see the AT&T 954 line, you can order it online.

ATT FAQs
http://telephones.att.com/attui/support/faqlist.cfm?NavID=398
Here are some common phone problems, and their solutions. You may be
able to troubleshoot the phone here, if you're having problems.

Product Support
http://telephones.att.com/attui/support/contact/Req_Info_Action.cfm?ReqType=ProdProb
Also, you can contact AT&T here, and ask them for a copy of the 955
manual, which looks like it is the closest replacement to your model.

Search Strategy:
I just downloaded a manual and knew where to look.

I hope this helps you! If you need any clarification of my answer,
please let me know before you rate it. Thank you!
nvwriter-ga

Nicely done!