You have to synchronize the time on both machines. Both machines must be within a few minutes of each other (I think the maximum is 3 or 5 minutes variance allowed), once they are talking you can set the workstations up to synchronise off the servertime. You can use your watch to set up one machine and then race to the other and do the same, they should be close enough to link.
With difficult cases I make sure of the time by accessing the Internet and get the time off the default MS time server. Where I am not sure of the local arrangements I usually do this via my own dial-up account by temporarily setting it up on each machine in turn and using my external modem, after the time is reset by the system I delete the account and modem.