[ntp:questions] Re: NTP4 has 3 different time formats! Namly (32, 64, 128) bits wide

Terje Mathisen terje.mathisen at hda.hydro.com
Tue Jul 18 10:40:46 UTC 2006

Ulrich Windl wrote:
> mayer at ntp.isc.org (Danny Mayer) writes:
> [...]
>> Well VMS always used 64 bits for time. Windows has now added a 64 bit
>> version of time_t and introduced 64-bit time functions. I don't think
>> that the *BSD's will be far behind. Dunno about Linux or Solaris.
> Talking about 128bit time formats or so: With today's computing power (just
> think of MP3 decoders), a switch to BCD coded time in 128 bit should be
> sufficient:
> Byte#: 1 2  3  4  5  6  7  8  910 111213 141516
> Value:2006-07-18 09:26:13.12 1234 567890 123456
> So you'd have significant sub-picosecond resolution and peace until year
> "9999".

Not at all, unfortunately!

Your time format is perfect for recording civilian events, but just as 
useless as "UTC_with_pretend_no_leapseconds" for NTP which needs a 
monotonic time scale. :-(

I.e. we need both ISO style date/time and TAI, and it is only for past 
events that you can know how to do an exact conversion to/from these 

- <Terje.Mathisen at hda.hydro.com>
"almost all programming can be viewed as an exercise in caching"

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