Graphql API - contributionsCollection and strange datetime related behavior

[aliok]

Select Topic Area

Bug

Body

I want to fetch contributions of a user in a datetime range.

query GetSummary2 {
  user(login:"shikharish"){
    contributionsCollection(from:"2024-04-07T00:00:00Z", to:"2024-04-08T00:00:00Z"){
      startedAt
      endedAt
      pullRequestContributionsByRepository(maxRepositories:100){
        contributions(first:100){
          nodes{
            pullRequest{
              createdAt
            }
          }
        }
      }
    }   
  }
}

Output:

{
  "data": {
    "user": {
      "contributionsCollection": {
        "startedAt": "2024-04-07T00:00:00Z",
        "endedAt": "2024-04-08T00:00:00Z",
        "pullRequestContributionsByRepository": [
          {
            "contributions": {
              "nodes": [
                {
                  "pullRequest": {
                    "createdAt": "2024-04-07T21:45:34Z"
                  }
                }
              ]
            }
          }
        ]
      }
    }
  }
}

This is good. There's only 1 PR available and its creation time fits in the given datetime range.

Problem 1

Now, change the to value to 1 second before:

query GetSummary2 {
  user(login:"shikharish"){
    contributionsCollection(from:"2024-04-07T00:00:00Z", to:"2024-04-07T23:59:59Z"){
      startedAt
      endedAt
      pullRequestContributionsByRepository(maxRepositories:100){
        contributions(first:100){
          nodes{
            pullRequest{
              createdAt
            }
          }
        }
      }
    }   
  }
}

Output:

{
  "data": {
    "user": {
      "contributionsCollection": {
        "startedAt": "2024-04-07T00:00:00Z",
        "endedAt": "2024-04-07T23:59:59Z",
        "pullRequestContributionsByRepository": []
      }
    }
  }
}

No PRs found! PR's creation datetime is in the given range though!

Problem 2

Change the from to some datetime after the PR creation date:

query GetSummary2 {
  user(login:"shikharish"){
    contributionsCollection(from:"2024-04-08T00:00:00Z", to:"2024-04-09T00:00:00Z"){
      startedAt
      endedAt
      pullRequestContributionsByRepository(maxRepositories:100){
        contributions(first:100){
          nodes{
            pullRequest{
              createdAt
            }
          }
        }
      }
    }   
  }
}

Output:

{
  "data": {
    "user": {
      "contributionsCollection": {
        "startedAt": "2024-04-08T00:00:00Z",
        "endedAt": "2024-04-09T00:00:00Z",
        "pullRequestContributionsByRepository": [
          {
            "contributions": {
              "nodes": [
                {
                  "pullRequest": {
                    "createdAt": "2024-04-07T21:45:34Z"
                  }
                }
              ]
            }
          }
        ]
      }
    }
  }
}

That PR is still found, even though its creation date is not in the given range.

[ahpook]

Hmm, my first thought was that there was a fixed offset in the way PR dates were stored vs queried. But I tried to bisect some times that would return that PR vs not return it and found that crossing day boundaries gave false positives, but there's also a false negative in the time range. Here's my results:

 contributionsCollection(from:"2024-04-07T00:59:00Z", to:"2024-04-07T23:00:00Z"){  # wrongly missing
 contributionsCollection(from:"2024-04-07T00:00:00Z", to:"2024-04-08T01:00:00Z"){  # correctly present
 contributionsCollection(from:"2024-04-07T23:59:00Z", to:"2024-04-08T00:00:00Z"){  # wrongly shows up
 contributionsCollection(from:"2024-04-08T00:59:00Z", to:"2024-04-08T23:00:00Z"){  # wrongly shows up
 contributionsCollection(from:"2024-04-08T23:59:00Z", to:"2024-04-09T00:00:00Z"){  # wrongly shows up
 contributionsCollection(from:"2024-04-09T00:59:00Z", to:"2024-04-09T10:00:00Z"){  # correctly empty

I'll look into this more, it's an interesting puzzle 🕵️

[LangLangBart]

I guess the user's time zone was used; shikharish seems to be from India (UTC+05:30). The PR is counted for the 8th of April, rather than the 7th.

Pull requests and issues opened on GitHub use your browser's time zone. Those opened via the API use the timestamp or time zone specified in the API call.

Source: Viewing contributions on your profile - GitHub Docs

What seems to be broken is that the time offset 00:00:00Z needs to be provided to make a successful GraphQL query, but it has no effect at all.