On 18 September 2013 10:59, Meno Hochschild <mhochschild@gmx.de> wrote:
So I support the removal, since I think the discussed data obviously appear to be of very questionable nature. We cannot even consider the discussed data as "our best estimate". Of course, there is no 100% guarantee - no black and white. If someone can know it better then it is easy to add the lost data again. But we should really not let the users in the state of wrong assumptions. Stability of data should not be the primary concern, rather correctness. And most users (near 100%) don't care about old that is to say archeological timezone data.
Pre-1970 data matters to some more than others. I can see a range of positions: a) delete all pre-1970 data b) only have Zones for areas distinct after 1970, other IDs are Links, full data where available for each Zone c) only have IDs for areas distinct after 1970, full data where available for each ID d) create new IDs where data only differs before 1970 I'm arguing for (c), which I previously believed was the tzdb's goal. The data deletion is based on (b). The quality of data deleted is also of different value to different people. I'll try to explain it in a different way... We know that the quality of the historic data for the Carribean is dubious. Lets give it an accuracy rating of 20%. One argument is that removing data with 20% accuracy is a good thing, and that is an understandable position. However, its important to look at the consequences of the deletion. Previously, location A (eg. Guadeloupe) had a 20% accuracy rating for its historic data. After the change it still has a 20% accuracy rating just with different data. But, that 20% accuracy rating refers to location B (eg. Port of Spain). From the perspective of location A, the accuracy is now lower, say 5%, because 20% accurate data for location B clearly is even less accurate for location A. I understand that the distinction here is fine. But its rather like saying "we published a guess 10 years ago for when the first factory opened in Brussels, but it now OK to replace that data with the guess we made for when the first factory opened in London" (assuming we recorded factory opening dates). I value each guess being distinct for each location in the absence of better information. Stephen