[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
time resolution (was Re: six-page binary format draft)
-----BEGIN PGP SIGNED MESSAGE-----
At 04:10 PM 11/24/97 GMT, Paul Leyland wrote:
>> > The ISO date format "yyyy-mm-dd hh:mm:ss" is valid for another 9000
years.
>>
>> Yes, please use that format. And if you permit 5, 6, 7... digit years,
>> then it has no built in obsolescence at all.
>
>While we are considering the question, is the second a fine enough
>quantum? It's not at all obvious to me that it is. If you permit (but
>not require) the seconds field to have a decimal fraction portion we get
>around that limitation as well. The binary format might represent the
>fraction as, say, integer number of nanoseconds.
I argued at one point to cut it off at 1 minute.
I'm fond of pointing out that Rivest and Lampson did for namespaces what
Einstein did for spacetime. It's time we pay attention to old fashioned
Relativity here, too.
There is no global spacetime. It is not possible to synchronize clocks.
The closest we can come to that is with error limits, given our knowledge of
the minimum and maximum delay in getting a time report. If there were the
master atomic clock on the net that still doesn't give us sub-second
resolution of time setting.
On the other hand, we can be reasonably sure of getting clocks to agree +/-
30 seconds, so maybe 1 minute resolution of times would be appropriate.
- Carl
-----BEGIN PGP SIGNATURE-----
Version: PGP for Personal Privacy 5.0
Charset: noconv
iQCVAwUBNHniVRN3Wx8QwqUtAQFogQP9Fzx4r4gpPUBvL93xUENT926eUWMkDQks
tyF3PNe0AIhdpT1IPWE7VCM4XMJn0TzROemfbKr5nSyJxesngbyGpdUmUDlLouSm
3r5SwmAKf01EFdlrPXbREOTr4123wgm9CnBjldSoukmEEBxafBgFIA6s+xtSgmUL
MKNo2yoAciE=
=GFsx
-----END PGP SIGNATURE-----
+------------------------------------------------------------------+
|Carl M. Ellison cme@cybercash.com http://www.clark.net/pub/cme |
|CyberCash, Inc. http://www.cybercash.com/ |
|207 Grindall Street PGP 08FF BA05 599B 49D2 23C6 6FFD 36BA D342 |
|Baltimore MD 21230-4103 T:(410) 727-4288 F:(410)727-4293 |
+------------------------------------------------------------------+
Follow-Ups:
References: