On Wed, 11 Jun 2025 at 13:57, PATAN JEELAN BASHA via tz <[email protected]> wrote:
> Just one quick question—since TZif3 is available and is a newer format and > technically a higher version than TZif2. > is there a specific reason why the IANA time zone database continues to > use TZif2? Per tzfile.5, which describes the file format, under "Interoperability considerations": "Other than version 1, writers should generate the lowest version number needed by a file's data. For example, a writer should generate a version 4 file only if its leap second table either expires or is truncated at the start. Likewise, a writer not generating a version 4 file should generate a version 3 file only if TZ string extensions are necessary to accurately model transition times." In short, this is done intentionally to maximize backwards compatibility. -- Tim Parenti
