Leo Bodnar <l...@leobodnar.com> wrote: > Assume that the device does not have any reliable long term non-volatile > memory that you can update.
> In the absence of any clues your only reliable piece of knowledge is > that the cold start date is somewhere after the date of manufacturing > or, most often, firmware compilation date. There's another relatively simple clue in the old GPS signal: the leap second count! A device manufacturer could teach it what the leap second count was at manufacturing time, and how to predict a lower bound on the leap second count in the future (with a suitable safety margin / fudge factor) which should allow it to live a bit more than 20 years. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ Gibraltar Point to North Foreland: Northeasterly 5 or 6, occasionally 7 in south. Moderate. Showers at first in south. Good, occasionally moderate at first. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
