Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!uunet!lll-winken!aunro!alberta!cpsc.ucalgary.ca!news
From: nickolas@cpsc.ucalgary.ca (Nickolas Chondropoulos)
Newsgroups: sci.electronics
Subject: Re: Accurate Real Time Clock Needed!
Keywords: Smartwatch, dallas semiconductor
Message-ID: <1991Jun7.175523.2848@cpsc.ucalgary.ca>
Date: 7 Jun 91 17:55:23 GMT
References: <1991Jun7.085330.8619@cc.curtin.edu.au>
Organization: U. of Calgary Computer Science
Lines: 6

I'm not sure if this would do the trick but look into the DS1216E by Dallas 
Semiconductor.  It is a 28 pin Smartwatch and can sit under any ROM on the bus.
It is accurate to 1 sec/month, good for a century and has a lithium battey built
in that lasts for 10 years.  Usual price up here in Calgary is ~$35.00 CAN.

Nick.