[tz] Inappropriate project direction

Stephen Colebourne scolebourne at joda.org
Tue Feb 6 16:13:51 UTC 2018

In the last few years, the following changes have been made to the
tzdb project. Each of these

- added no value
- had a cost that far exceeded the benefits
- should not have happened

1) Removal of Zone definitions from many countries.

While the Zone definitions may have been the same across different
countries, it was never appropriate to merge the time-zones of
multiple different countries (backzone being the result).

- the change caused LMT values to be lost
- downstream consumers had to change logic wrt the meaning of backzone
- it was culturally insensitive to not provide a primary Zone entry
for some countries

2) Removal of textual short zone names.

While these names may well have been invented in some cases, the had
often become de facto standards

- end-users complained about the loss of textual names
- downstream consumers had to change logic to handle numeric-style identifiers

3) Move to a niche archive format

The main archive format was changed from the well-known and widely
supported gz to the niche lz format. There was and is no justification
for using a niche format on a project as important as this one.

- downstream consumers need to find and use the niche format
- Windows does not have proper support for the niche format

4) Negative SAVE values

Despite being a known fact in tzdb since 2005, and despite being
warned not to in advance, a decision to re-interpret the meaning of
Ireland DST was pushed through.

- downstream consumers broke
- the interaction with CLDR is incompatible with negative DST
- the change has no impact on actual times
- even if someone thought it was broken, there are no benefits to
making the change

5) Fractional seconds

A desire to fix subsecond data from over 50 years ago.

- downstream consumers will break
- the number of people who care is vanishingly small

Were recent discussions a one-off, I might be prepared to let things
lie, but as can be seen, there is a pattern here. Not one of these
changes has added value to the project. Not one of them has been
necessary to the primary mission of recording what governments are
doing to their clocks now, nor even in the last 40 years. Worse, the
majority are driven by a notion that getting the data "pure" trumps
all problems reported by downstream consumers.

It is long past time to accept that tzdb needs to focus on the primary
mission - recording current government changes in a stable, backwards
compatible manner.

Tinkering needs to stop.


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