On Wed, 2024-03-06 at 23:46 -0800, Paul Eggert wrote:
On 3/6/24 13:29, Benjamin Drung via tz wrote:
the Debian/Ubuntu package uses BACKWARD=backward PACKRATDATA=backzone.
Why is that? In other words, what bug report prompted the use of PACKRATDATA? That may help figure out a reasonable fix, if any is needed.
This is the bug report: https://bugs.launchpad.net/ubuntu/+source/tzdata/+bug/2003797 We have lots of users and some of them care about pre-1970 timestamps. We want to satisfy them as well.
The resulting tzdata.zi has the timezone Africa/Asmara, but Africa/Asmera points to Africa/Nairobi instead of the existing Africa/Asmara
'backzone' contains out-of-scope and often-wrong data dating back to an older way of doing things. The 'backzone' data entries are not maintained and are not necessarily compatible with the in-scope data in 'africa', 'asia', etc.
There is tension between being bug-for-bug compatible with the older tzdata, and being compatible with in-scope data and/or with other platforms. The 'backzone' file is designed for the former case; this minimizes maintenance effort, since it's relatively easy to just keep the 'backzone' data the way it was. I wouldn't want to take on the maintenance burden for the latter case, as that'd be quite a mess.
The goal is to get the pre-1970 data back, but keep it unchanged for post 1970. -- Benjamin Drung Debian & Ubuntu Developer