Hey all,

I have a LAN which is totally disconnected from Internet.
Therefore, there is no possible syncrhonisation with online time reference.

Thus, I need an hardware source of time to maintain synchronisation between systems.

Do you know what could to provide the time ?

PS: I can't use radio device, I can't receive radio in the room.

Thanks

A guess...

Can't you set up one of your machines as a time protocol server for the others? That is what NTP is for, although you would not be able to guarantee the accuracy of your own time standard in relation to that other standard in the rest of the world.

Does the accuracy have to be greater than the time clock on your most accurate machine, at GMT plus/minus a few seconds as you set it, if you check and reset it regularly?

http://www.ntp.org/

Otherwise, Google points to hardware solutions based on using GPS, but if you have no radio signal, can you receive a GPS signal? Is there no way to rig an antenna out a window?