Vamsi-klu opened a new pull request, #68150: URL: https://github.com/apache/airflow/pull/68150
`DayWindow` assumed every day has 24 hours, so with a local-timezone upstream mapper a spring-forward day's rollup was held forever (an expected hourly key — e.g. `2024-03-10T02` — never occurs) (#68004). `DayWindow` is now DST-aware: when paired with a local-timezone upstream mapper it enumerates the real local hours of the calendar day by stepping through the period in UTC, yielding **23** expected keys on a spring-forward day and 24 otherwise, so the rollup can actually be satisfied. With a UTC/naive mapper the behavior is unchanged (24). The timezone is threaded from the mapper into the window at call time, so windows stay serialization-free. Scope note (fall-back day): the repeated local 01:00 collapses to a single key unless the upstream `input_format` carries the UTC offset (`%z`); the window no longer hangs, but full 25-key coverage is left as a follow-up that also needs an `encode_upstream` change. closes: #68004 --- ##### Was generative AI tooling used to co-author this PR? - [X] Yes — Claude Code (Opus 4.8) Generated-by: Claude Code (Opus 4.8) following [the guidelines](https://github.com/apache/airflow/blob/main/contributing-docs/05_pull_requests.rst#gen-ai-assisted-contributions) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
