[GitHub] [airflow] john-bodley opened a new pull request, #25290: [docs] Update DAG run to clarify when a DAG actually runs

[GitBox <gi...@apache.org>]

john-bodley opened a new pull request, #25290:
URL: https://github.com/apache/airflow/pull/25290

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   I was trying to decipher when exactly a DAG run associated with a given `ds` would run, i.e., at midnight (00:00) or midnight (24:00). Per the docs, 
   
   > A DAG run is usually scheduled after its associated data interval has ended, to ensure the run is able to collect all the data within the time period. In other words, a run covering the data period of 2020-01-01 generally does not start to run until 2020-01-01 has ended, i.e. after 2020-01-02 00:00:00.
   
   and observing DAG runs it seems like these DAG runs occur at the end of said day rather than the beginning. 
   
   This PR updates the documentation—hopefully I got this correct—to:
   
   1. Remove confusion. As reported in [this](https://en.wikipedia.org/wiki/12-hour_clock#Confusion_at_noon_and_midnight) Wikipedia article there's some ambiguity around what day midnight is associated with and thus I felt being explicit—via the use of a 24 hour clock—would help clarify.
   2. Address inaccuracies/inconsistencies, i.e., some DAG presets state "midnight" whereas others reference the morning— "midnight on Sunday morning". Additionally I think "... at the _beginning_ of the hour" should be "... at the _end_ of the hour" assuming these windows operate in a consistent manner.
   
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[GitHub] [airflow] boring-cyborg[bot] commented on pull request #25290: [docs] Update DAG run to clarify when a DAG actually runs

[GitBox <gi...@apache.org>]

boring-cyborg[bot] commented on PR #25290:
URL: https://github.com/apache/airflow/pull/25290#issuecomment-1195006871

   Awesome work, congrats on your first merged pull request!
   


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[GitHub] [airflow] uranusjr merged pull request #25290: [docs] Update DAG run to clarify when a DAG actually runs

[GitBox <gi...@apache.org>]

uranusjr merged PR #25290:
URL: https://github.com/apache/airflow/pull/25290


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