On 3 September 2013 15:47, Paul Eggert <eggert@cs.ucla.edu> wrote:
Brian Inglis wrote:
merging zones with different Standard Time start date loses useful historical data
That's not a problem for the proposed change, because in this particular case, no useful historical data are lost. There is no real evidence that the start dates actually differed. All we have is some guesswork from Shanks. The Shanks data often contain guesswork, and the abovementioned transition dates from LMT are almost certainly part of that guesswork.
The associated time zone abbreviations are also guesswork (in this case, my guesswork and not Shanks'), so they do not contain any useful historical data either.
Your long experience with the tzdb leads you to assert that these are guesswork, therefore OK to delete. Unfortunately, the consumers of the tzdb see the data as fact, and since the data has been there for many years that simply reaffirms the "fact" status. I'd also suggest that Shanks information has at least some degree of thought behind it, certainly better than picking up the thoughts of some other location that has always been under another jurisdiction. I really wasn't joking when I suggested that pretty much no refactoring is now possible. Its certainly the case that pretty much every refactoring you can think of has some data loss. thanks Stephen