[ntp:questions] NTP vs BCD vs Unix ('unsinged int' or 'unsigned long int') time format coding: is there a sensible explaination for the differences in coding?

Max Power mikehack at u.washington.edu
Mon May 8 20:01:10 UTC 2006


NTP vs BCD vs Unix ('unsigned int' or 'unsigned long int') time format 
coding: is there a sensible explanation for the differences in coding?

I like [raw] Unix Time's lack of ambiguity is best suited for setting the 
clocks on most computers and as a universal unambiguous binary time and date 
format, but NTP-64 and NTP-128 are best suited for scientific and business 
applications (including modern OS file system time stamps).

BCD seems to be best suited for consumer devices, for its ease of 
decoding -- but BCD formats are not as standardized as NTP nor are they as 
unambiguous as [raw] Unix Time. BCD's only advantage is ability to be 
designed for 'bit averaging for error correction. Raw Unix Time's ability to 
use bit averaging is only slightly less optimum than BCD, as raw Unix Time 
has about 6 volatile bits in the last LSB bit positions.





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