On the two portables that dual boot, I just set the kept adjusting the Time Zone until the clock was right in OS X.

I know its not the best, but I don't look at the Zones much.

---

Tiger: G4 PowerPC Dual Core 400 Mhz w/640 MB RAM
20 Gig ATA HD all HFS+
Internal DVD
Access to Server
True Tiger

Leopard: Acer Intel Atom Dual [email protected] w/1 Gig Ram
160GB HD-133GB NTFS, 15.68GB HFS+
SD slot
No Net access
iDeneb 1.6 Lite

Compaq SR5710F [email protected] w/3 Gigs Ram
80 Gig ATA HD (NTFS - Vista)
200 Gig ATA HD (NTFS-Data)
Access to Server

Server: Compaq 1.8 Single Core Windows Server 2003 Enterprise Edition
~2 TB online....