Re: Getting time from a GPRS modem



In comp.arch.embedded,
Didi <dp@xxxxxxxxxxx> wrote:
On Mar 15, 10:22 am, Stef <stef...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:

I think RFC868 is the shortest RFC I've seen so far, only 2 pages.
It looks nice and simple, but there seem to be some inconsistencies:

* Time in Seconds from 1900-01-01 (like NTP)
* 32 bit binary number (signed or unsigned?)
* Will serve till 2036 (ah, must be unsigned then)
* But the there is this example:
  -1,297,728,000 corresponds to 00:00 17 Nov 1858 GMT.
  So it is a signed 32 bit afterall?
  But that would limit the range from 1832 - 1968 :-(


Hah, hadn't noticed that. The servers I have talked to worked
unsigned, so does the DPS server I wrote (does ntp and rfc868).
I vaguely remember servers which were advertised as ntp only did
after all serve rfc868 as well, but it is being abandoned IIRC.
Has been in that state for >30 years I guess :D .
Well, just tried it on a server which I think used to work a few
years back - only NTP today.

Yes, I think they meant unsigned but got carried away in the examples
section. RFC868 is from 1983 and is superseded by NTP. Just posted
the above comment on faqs.org, it's an RFC afterall. :-)

Also found this NIST page: http://www.nist.gov/pml/div688/grp40/its.cfm
Says time.nist.gov has dropped support for RFC868, but other NIST
servers wil still respond to RFC868 requests.


--
Stef (remove caps, dashes and .invalid from e-mail address to reply by mail)

Pity the meek, for they shall inherit the earth.
-- Don Marquis
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