[XML-SIG] Re: RSS and stuff

Walter Underwood wunder@infoseek.com
Fri, 04 Jun 1999 08:49:44 -0700

At 06:04 PM 6/2/99 -0700, Dan Libby wrote:
>Walter, thanks for the code example.
>> And let's try to avoid using seconds-since-the-epoch in external
>> formats. We're just now doing the Y2K thing, so I don't think it
>> is a good idea to use formats that fall apart in 2037.
>I thought it was 2038.  ;-)   Seems like we should all be using 
>long longs by then - greater than 32 bits anyway, so I'm not sure 
>it is such a big problem.

We've been parsing dates for date search in our engine, and the
Unix timestamp has real problems. No time zone, for example.

>Anyway, the nice thing about the integer is that they are guaranteed 
>accurate to the second. With ISO 8601, the receiver needs to round 
>(nearest day, hour, minute, second).

With the timestamp, does the number of seconds include all the 
leap seconds since 1970? It should, but does it? Does Apache on
Amiga do the right thing? To be pedantic, the Unix timestamp
format is precise but may not be accurate.

Lots of content has a meaningful precision other than one second.
Press Releases are on a certain day. Books are published in a
particular month. Forcing meaningless precision on those things 
is a mistake.

Finally, the seconds thing totally falls apart if you need to express
dates outside it's tiny range: photograph taken in 1893, an HP atomic 
clock app note written in 1964, etc.

Internally, the right way to handle this is to carry a precision 
along with the time. DCE has some routines to do this. The DCE
Time Services Spec is listed here, but it's not free:


I'll see if I can hunt down some non-pay man pages.

Walter R. Underwood
wunder@best.com (home)
http://software.infoseek.com/cce/ (my product)