Hello!

I'm developing an application using the JavaScript Intl API (which is relying on the IANA tz db) for converting between local time and UTC.

I started receiving error reports from users about wrong calculations (particularly from Denmark in the 1940's), and I discovered that in some cases daylight saving time was applied in a way not in accordance to historical facts.

I investigated the IANA tz database files and I discovered that a change has happened in version 2022b (in the file "europe"). Compared to the earlier version (2022a), 4 zones seem to have their rules removed and instead linked to Europe/Berlin:

Link Europe/Berlin Arctic/Longyearbyen
Link Europe/Berlin Europe/Copenhagen
Link Europe/Berlin Europe/Oslo
Link Europe/Berlin Europe/Stockholm

This, evidently, is not correct, and will result in erroneous results for these zones.

Best wishes,

Anders Rosendahl