{HEAD ~ A global time signal} from a global time reference or {TAIL ~ common time source} can be used to calculate a common view based clock offset between the two clocks 
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{ HEAD ~ A global time signal } from a global time reference or { TAIL ~ common time source } can be used to calculate a common view based clock offset between the two clocks
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH