[time-nuts] Thunderbolt GPS rollover

[Tom Van Baak]

> Mike,
> The problem with your solution is that the receiver can get an error in  
> calculating the year value and if it writes a number greater than it  
> actually is into eeprom, the next time it powers on it will be forced to go  
> forward 19 years in time.  And since it is not allowed to go backwards in  
> time, it will always have the wrong date.  I have worked with many software  
> engineers doing GPS receiver design, believe me, there is no fool proof  
> solution to this.
> Doug, K4CLE

I suspect most GPS receivers know how to calculate the year and
how to reliably write it EEPROM. Nevertheless, there are fool proof
ways to distinguish past, current, and the next few 19.6 year blocks:
www.google.com/patents/US5923618
http://www.leapsecond.com/notes/gpswnro.htm

/tvb