Align dataset refresh window with the ISO week it is labelled with

.github/workflows/collect-and-screen.yml

@@ -7,10 +7,10 @@ permissions:
 on:
   workflow_dispatch:
     inputs:
-      since-days:
-        description: "Look at PRs merged within the last N days"
+      weeks-ago:
+        description: "Collect PRs merged during the ISO week N weeks back (1 = last completed week)"
         required: false
-        default: "7"
+        default: "1"
         type: string
       repo:
         description: "Source GitHub repository (OWNER/REPO)"
@@ -53,21 +53,32 @@ jobs:
         run: |
           $ErrorActionPreference = 'Stop'
 
-          $week = [System.Globalization.ISOWeek]::GetWeekOfYear((Get-Date).ToUniversalTime()).ToString('00')
-          $branch = "dataset/week-$week"
+          Import-Module ./scripts/BCBenchUtils.psm1 -Force
+
+          # Label the branch/PR with the ISO week the candidates were merged in — the last
+          # completed week — not the week the job happens to run in.
+          $window = Get-IsoWeekWindow -WeeksAgo ${{ inputs.weeks-ago || '1' }}
+          $branch = "dataset/week-$($window.Label)"
+          $mergedSince = $window.Start.ToString('yyyy-MM-ddTHH:mm:ssZ')
+          $mergedUntil = $window.End.ToString('yyyy-MM-ddTHH:mm:ssZ')
+          Write-Host "Collecting PRs merged in ISO week $($window.Label): $mergedSince .. $mergedUntil"
 
           git config user.name 'github-actions[bot]'
           git config user.email 'github-actions[bot]@users.noreply.github.com'
           git checkout -B $branch
 
           .\scripts\Collect-And-Screen.ps1 `
             -Repo '${{ inputs.repo || 'microsoft/BCApps' }}' `
-            -SinceDays ${{ inputs.since-days || '7' }} `
+            -MergedSince $mergedSince `
+            -MergedUntil $mergedUntil `
             -Limit ${{ inputs.limit || '50' }} `
             -BaseBranch '${{ inputs.base-branch || 'main' }}' `
             -SummaryFile $env:GITHUB_STEP_SUMMARY `
             -CollectedFile "$PWD/collected.json"
 
+          Add-Content -Path $env:GITHUB_OUTPUT -Value "merged-since=$mergedSince"
+          Add-Content -Path $env:GITHUB_OUTPUT -Value "merged-until=$mergedUntil"
+
           if (-not (git status --porcelain)) {
             Write-Host 'No dataset changes; nothing to push.'
             Add-Content -Path $env:GITHUB_OUTPUT -Value 'branch='
@@ -199,7 +210,9 @@ jobs:
             -JobsFile jobs.json `
             -RunUrl '${{ steps.validate.outputs.run-url }}' `
             -Repo $repo `
-            -Week $week | Set-Content -Path pr-body.md -Encoding utf8
+            -Week $week `
+            -MergedSince '${{ steps.run.outputs.merged-since }}' `
+            -MergedUntil '${{ steps.run.outputs.merged-until }}' | Set-Content -Path pr-body.md -Encoding utf8
 
           $title = "Dataset refresh: week $week candidates from $repo"
           $existing = gh pr list --head $branch --state open --json number --jq '.[0].number // empty'

scripts/BCBenchUtils.psm1

@@ -589,4 +589,44 @@ function Get-LatestReleaseBranch {
     return $latest.Name
 }
 
-Export-ModuleMember -Function Get-BCCredential, Invoke-GitCloneWithRetry, Get-EnvironmentVariable, Write-Log, Invoke-GitApplyPatch, Update-AppProjectVersion, Get-BCBenchDatasetPath, Get-BCBenchEntryVersion, Get-RepoCloneInfo, Get-LatestReleaseBranch
+<#
+.SYNOPSIS
+    Resolves the UTC bounds and label of a completed ISO-8601 week.
+.DESCRIPTION
+    Returns the Monday 00:00:00 UTC start and Sunday 23:59:59 UTC end of the ISO week that
+    is $WeeksAgo weeks before $ReferenceDate, so a weekly job labelled "week N" collects
+    exactly the work merged during week N instead of a trailing window that straddles two
+    weeks. $ReferenceDate is interpreted as UTC.
+.PARAMETER ReferenceDate
+    Date the window is measured back from. Defaults to now (UTC).
+.PARAMETER WeeksAgo
+    How many weeks back to go. 1 (default) is the last completed week.
+.OUTPUTS
+    PSCustomObject with Year, Week, Label ("2026-29"), Start and End (UTC DateTime).
+.EXAMPLE
+    $window = Get-IsoWeekWindow -WeeksAgo 1
+#>
+function Get-IsoWeekWindow {
+    [CmdletBinding()]
+    [OutputType([pscustomobject])]
+    param(
+        [datetime]$ReferenceDate = [datetime]::UtcNow,
+        [int]$WeeksAgo = 1
+    )
+
+    $shifted = $ReferenceDate.Date.AddDays(-7 * $WeeksAgo)
+    $daysSinceMonday = ([int]$shifted.DayOfWeek + 6) % 7
+    $start = [datetime]::SpecifyKind($shifted.AddDays(-$daysSinceMonday), [DateTimeKind]::Utc)
+    $year = [System.Globalization.ISOWeek]::GetYear($start)
+    $week = [System.Globalization.ISOWeek]::GetWeekOfYear($start)
+
+    [pscustomobject]@{
+        Year  = $year
+        Week  = $week
+        Label = '{0}-{1:00}' -f $year, $week
+        Start = $start
+        End   = $start.AddDays(7).AddSeconds(-1)
+    }
+}
+
+Export-ModuleMember -Function Get-BCCredential, Invoke-GitCloneWithRetry, Get-EnvironmentVariable, Write-Log, Invoke-GitApplyPatch, Update-AppProjectVersion, Get-BCBenchDatasetPath, Get-BCBenchEntryVersion, Get-RepoCloneInfo, Get-LatestReleaseBranch, Get-IsoWeekWindow

scripts/Collect-And-Screen.ps1

@@ -11,8 +11,17 @@ the working tree. Committing/pushing is left to the caller (e.g. the
 .PARAMETER Repo
 Source GitHub repository (OWNER/REPO). Defaults to microsoft/BCApps.
 
-.PARAMETER SinceDays
-Look at PRs merged within the last N days.
+.PARAMETER MergedSince
+Only consider PRs merged at or after this UTC timestamp (yyyy-MM-ddTHH:mm:ssZ).
+Defaults to the start of the ISO week selected by -WeeksAgo.
+
+.PARAMETER MergedUntil
+Only consider PRs merged at or before this UTC timestamp (yyyy-MM-ddTHH:mm:ssZ).
+Defaults to the end of the ISO week selected by -WeeksAgo.
+
+.PARAMETER WeeksAgo
+Which completed ISO week to collect when -MergedSince/-MergedUntil are omitted.
+1 (default) is the last completed week.
 
 .PARAMETER Limit
 Maximum number of merged PRs to consider.
@@ -24,13 +33,15 @@ Only consider PRs merged into this base branch. Defaults to main.
 Optional path to append a markdown summary to (e.g. $env:GITHUB_STEP_SUMMARY).
 
 .EXAMPLE
-.\scripts\Collect-And-Screen.ps1 -SinceDays 2 -Limit 5
+.\scripts\Collect-And-Screen.ps1 -WeeksAgo 1 -Limit 5
 #>
 
 [CmdletBinding()]
 param(
     [string]$Repo = 'microsoft/BCApps',
-    [int]$SinceDays = 7,
+    [string]$MergedSince,
+    [string]$MergedUntil,
+    [int]$WeeksAgo = 1,
     [int]$Limit = 200,
     [string]$BaseBranch = 'main',
     [string]$SummaryFile,
@@ -41,18 +52,35 @@ $ErrorActionPreference = 'Stop'
 
 Import-Module (Join-Path $PSScriptRoot 'BCBenchUtils.psm1') -Force
 
+$window = Get-IsoWeekWindow -WeeksAgo $WeeksAgo
+$timestampFormat = 'yyyy-MM-ddTHH:mm:ssZ'
+if (-not $MergedSince) { $MergedSince = $window.Start.ToString($timestampFormat) }
+if (-not $MergedUntil) { $MergedUntil = $window.End.ToString($timestampFormat) }
+
+function ConvertTo-UtcDateTime {
+    param([string]$Value)
+    [datetime]::Parse($Value, [cultureinfo]::InvariantCulture,
+        [System.Globalization.DateTimeStyles]::AdjustToUniversal -bor [System.Globalization.DateTimeStyles]::AssumeUniversal)
+}
+
+$sinceUtc = ConvertTo-UtcDateTime $MergedSince
+$untilUtc = ConvertTo-UtcDateTime $MergedUntil
+if ($untilUtc -le $sinceUtc) { throw "MergedUntil ($MergedUntil) must be after MergedSince ($MergedSince)" }
+
+$isoWeek = Get-IsoWeekWindow -ReferenceDate $sinceUtc -WeeksAgo 0
+$weekLabel = if ($isoWeek.Start -eq $sinceUtc -and $isoWeek.End -eq $untilUtc) { " (ISO week $($isoWeek.Label))" } else { '' }
+
 $latestRelease = Get-LatestReleaseBranch -Repo $Repo
 if (-not $latestRelease) { throw "No releases/* branch found in $Repo" }
 $envVersion = $latestRelease -replace '^releases/', ''
 Write-Log "Latest release branch in $Repo`: $latestRelease (environment_setup_version=$envVersion)" -Level Info
 
-$since = (Get-Date).ToUniversalTime().AddDays(-$SinceDays).ToString('yyyy-MM-dd')
-Write-Log "Searching merged PRs in $Repo (base: $BaseBranch) since $since (limit $Limit)" -Level Info
+Write-Log "Searching merged PRs in $Repo (base: $BaseBranch) merged $MergedSince..$MergedUntil$weekLabel (limit $Limit)" -Level Info
 
 $requiredLabel = 'AL: Apps (W1)'
 $jqFilter = "[.[] | select((.labels | length) == 1 and .labels[0].name == `"$requiredLabel`") | .number]"
 $prsJson = & gh pr list --repo $Repo --state merged --base $BaseBranch --label $requiredLabel `
-    --search "merged:>=$since" --limit $Limit --json 'number,labels' --jq $jqFilter
+    --search "merged:$MergedSince..$MergedUntil" --limit $Limit --json 'number,labels' --jq $jqFilter
 if ($LASTEXITCODE -ne 0) { throw "gh pr list failed" }
 
 [int[]]$prs = ($prsJson | ConvertFrom-Json)
@@ -94,7 +122,7 @@ if ($SummaryFile) {
     $summary += ''
     $summary += "Env: ``$envVersion``"
     $summary += ''
-    $summary += "Window: last $SinceDays day(s) (since $since)"
+    $summary += "Window: $MergedSince .. $MergedUntil$weekLabel"
     $summary += ''
     $summary += "Considered: $($prs.Count)"
     $summary += ''

scripts/New-DatasetPrBody.ps1

@@ -14,7 +14,9 @@ param(
     [string]$JobsFile,
     [string]$RunUrl,
     [Parameter(Mandatory)][string]$Repo,
-    [Parameter(Mandatory)][string]$Week
+    [Parameter(Mandatory)][string]$Week,
+    [string]$MergedSince,
+    [string]$MergedUntil
 )
 
 $ErrorActionPreference = 'Stop'
@@ -47,8 +49,10 @@ function Format-EntryLine {
 $passed = @($entries | Where-Object { $j = $jobMap[[string]$_.Id]; $j -and $j.conclusion -eq 'success' })
 $failed = @($entries | Where-Object { $j = $jobMap[[string]$_.Id]; -not ($j -and $j.conclusion -eq 'success') })
 
+$mergeWindow = if ($MergedSince -and $MergedUntil) { " (merged $MergedSince .. $MergedUntil)" } else { '' }
+
 $lines = @(
-    "Automated dataset refresh: bug-fix candidates collected from ``$Repo`` for ISO week $Week.",
+    "Automated dataset refresh: bug-fix candidates collected from ``$Repo`` for ISO week $Week$mergeWindow.",
     '',
     '## ✅ Included (passed validation)',
     '',