dateutil/dateutil

tzfile reader only reads 32-bit (verson 0) zoneinfo files

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#462 opened on Sep 20, 2017

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 (4 comments) (4 reactions) (0 assignees)Python (2,189 stars) (470 forks)batch import
bugenhancementhelp wantedmedium-difficultytime zones

Description

The output of zic includes a 32-bit legacy section and a 64-bit section that encodes the transition times as 64-bit epoch times. Currently we're only reading the first one. What we should do is read the zoneinfo header to determine how long the first section is, seek to the end of that section and see if there's a second "version 2" section, and if so read that one instead, otherwise go back and finish reading the 32-bit version.

This will have almost no real effect at the moment.

Contributor guide

Tech stack
python
Domain
backend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
PythonBinary file I/Odateutil codebase basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
85
Research direction
The issue describes reading the zoneinfo file header to determine the size of the 32 bit section, then seeking to the end to check for a version 2 section (as per zic output). The relevant code is likely in the dateutil/tz/tzfile.py file. The comments in the issue may provide additional context, but the body gives clear steps. No linked PRs exist.