Re: [Tzdist] Existing and new data ...

[Paul Eggert <[e-mail]>]

On 12/10/2014 11:17 AM, Cyrus Daboo wrote:
> "changedsince" allows the client to request a "diff" in the list 
> action response - i.e., only get the list of time zones that have 
> changed. If we adopted the IANA tzdb version numbering scheme, then 
> every time a new version is released ALL time zones would be marked as 
> "new" since their version number has changed, even though the actual 
> time zone information (UTC offset, DST rules etc) is likely the same 
> for the majority of them.

First, thanks for writing that -- something like that should be in the 
document, if we have versions.

Second, though, this doesn't explain why changedsince uses dates and not 
version numbers.  If a client is using tz2014a and the server says 
tz2014b is the latest, why can't the client say "I've got version 
tz2014a of America/Los_Angeles; is that good enough?".  The fact that a 
client can't ask this suggests that versions and changedsince are two 
different mechanisms for attacking the same problem, which complicates 
the protocol unnecessarily.  It'd be better to have just one mechanism here.