diff --git a/Actions/.Modules/WorkflowPostProcessHelper.psm1 b/Actions/.Modules/WorkflowPostProcessHelper.psm1
new file mode 100644
index 000000000..1d192260d
--- /dev/null
+++ b/Actions/.Modules/WorkflowPostProcessHelper.psm1
@@ -0,0 +1,47 @@
+<#
+.SYNOPSIS
+Helper functions for WorkflowPostProcess action
+
+.DESCRIPTION
+Contains utility functions used by the WorkflowPostProcess action and its tests
+#>
+
+<#
+.SYNOPSIS
+Calculate the duration of a workflow from a start time
+
+.DESCRIPTION
+Calculates the duration in seconds from the provided start time to the current UTC time.
+Handles both DateTime objects and string representations in any date format that can be parsed by the invariant culture (e.g., ISO 8601 or other culture-independent formats).
+
+.PARAMETER StartTime
+The workflow start time as either a DateTime object or a string in any date format that can be parsed by the invariant culture (such as ISO 8601 or other culture-independent formats)
+
+.PARAMETER EndTime
+(Optional) The end time as a DateTime object. Defaults to the current UTC time.
+
+.EXAMPLE
+$duration = GetWorkflowDuration -StartTime "2025-12-12T10:00:00.0000000Z" -EndTime ([DateTime]::UtcNow)
+
+.EXAMPLE
+$duration = GetWorkflowDuration -StartTime ([DateTime]::UtcNow)
+#>
+function GetWorkflowDuration {
+    Param(
+        [Parameter(Mandatory = $true)]
+        $StartTime,
+        [Parameter(Mandatory = $false)]
+        $EndTime = [DateTime]::UtcNow
+    )
+
+    if ($StartTime -is [DateTime]) {
+        $workflowStartTime = $StartTime.ToUniversalTime()
+    } else {
+        $workflowStartTime = [DateTime]::Parse($StartTime, [System.Globalization.CultureInfo]::InvariantCulture, [System.Globalization.DateTimeStyles]::AdjustToUniversal)
+    }
+
+    $workflowDuration = $EndTime.ToUniversalTime().Subtract($workflowStartTime).TotalSeconds
+    return $workflowDuration
+}
+
+Export-ModuleMember -Function GetWorkflowDuration
diff --git a/Actions/WorkflowInitialize/WorkflowInitialize.ps1 b/Actions/WorkflowInitialize/WorkflowInitialize.ps1
index 5629ea421..9413e24ef 100644
--- a/Actions/WorkflowInitialize/WorkflowInitialize.ps1
+++ b/Actions/WorkflowInitialize/WorkflowInitialize.ps1
@@ -30,8 +30,9 @@ TestALGoRepository
 TestRunnerPrerequisites
 
 # Create a json object that contains an entry for the workflowstarttime
+# Use ISO 8601 format for locale-agnostic serialization
 $scopeJson = @{
-    "workflowStartTime" = [DateTime]::UtcNow
+    "workflowStartTime" = [DateTime]::UtcNow.ToString("o")
 } | ConvertTo-Json -Compress
 
 Add-Content -Encoding UTF8 -Path $env:GITHUB_OUTPUT -Value "telemetryScopeJson=$scopeJson"
diff --git a/Actions/WorkflowPostProcess/WorkflowPostProcess.ps1 b/Actions/WorkflowPostProcess/WorkflowPostProcess.ps1
index 9928ce944..eb1eb8bb4 100644
--- a/Actions/WorkflowPostProcess/WorkflowPostProcess.ps1
+++ b/Actions/WorkflowPostProcess/WorkflowPostProcess.ps1
@@ -68,8 +68,9 @@ function LogWorkflowEnd($TelemetryScopeJson, $JobContext, $AlGoVersion) {
     # Calculate the workflow duration using the github api
     if ($telemetryScope -and ($null -ne $telemetryScope.workflowStartTime)) {
         Write-Host "Calculating workflow duration..."
-        $workflowTiming= [DateTime]::UtcNow.Subtract([DateTime]::Parse($telemetryScope.workflowStartTime)).TotalSeconds
-        Add-TelemetryProperty -Hashtable $AdditionalData -Key 'WorkflowDuration' -Value $workflowTiming
+
+        $workflowDuration = GetWorkflowDuration -StartTime $telemetryScope.workflowStartTime
+        Add-TelemetryProperty -Hashtable $AdditionalData -Key 'WorkflowDuration' -Value $workflowDuration
     }
 
     # Log additional telemetry from AL-Go settings
@@ -102,6 +103,7 @@ function LogWorkflowEnd($TelemetryScopeJson, $JobContext, $AlGoVersion) {
 }
 
 Import-Module (Join-Path -Path $PSScriptRoot -ChildPath "..\TelemetryHelper.psm1" -Resolve)
+Import-Module (Join-Path -Path $PSScriptRoot -ChildPath "..\.Modules\WorkflowPostProcessHelper.psm1" -Resolve)
 
 try {
     LogWorkflowEnd -TelemetryScopeJson $telemetryScopeJson -JobContext $currentJobContext -AlGoVersion (GetAlGoVersion -ActionsRepo $actionsRepo -ActionRef $actionsRef)
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 3c7cd0000..c25448982 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -1,5 +1,6 @@
 ### Issues
 
+- Issue 2045 DateTime parsing fails on non-US locale runners in WorkflowPostProcess.ps1
 - Issue 2055 When using versioningStrategy 3+16, you get an error when building
 - AL-Go repositories with large amounts of projects may run into issues with too large environment variables
 
diff --git a/Tests/WorkflowPostProcess.Test.ps1 b/Tests/WorkflowPostProcess.Test.ps1
index dbcc2c104..36fea65a2 100644
--- a/Tests/WorkflowPostProcess.Test.ps1
+++ b/Tests/WorkflowPostProcess.Test.ps1
@@ -1,5 +1,6 @@
 Get-Module TestActionsHelper | Remove-Module -Force
 Import-Module (Join-Path $PSScriptRoot 'TestActionsHelper.psm1')
+Import-Module (Join-Path $PSScriptRoot '..\Actions\.Modules\WorkflowPostProcessHelper.psm1')
 $errorActionPreference = "Stop"; $ProgressPreference = "SilentlyContinue"; Set-StrictMode -Version 2.0
 
 Describe "WorkflowPostProcess Action Tests" {
@@ -25,4 +26,24 @@ Describe "WorkflowPostProcess Action Tests" {
 
     # Call action
 
+    It 'GetWorkflowDuration handles different culture formats correctly' {
+        $endTimeUTC = [DateTime]::Parse("2025-12-12T10:00:01.0000000Z")
+
+        # Test UTC start time
+        $workflowDuration = GetWorkflowDuration -StartTime "2025-12-12T10:00:00.0000000Z" -EndTime $endTimeUTC
+        $workflowDuration | Should -Be 1
+
+        # Test en-US culture format
+        $workflowDuration = GetWorkflowDuration -StartTime "12/12/2025 10:00:00 AM" -EndTime $endTimeUTC
+        $workflowDuration | Should -Be 1
+
+        # Test de-DE culture format
+        $workflowDuration = GetWorkflowDuration -StartTime "12.12.2025 10:00:00" -EndTime $endTimeUTC
+        $workflowDuration | Should -Be 1
+
+        # Test da-DK culture format
+        $workflowDuration = GetWorkflowDuration -StartTime "12-12-2025 10:00:00" -EndTime $endTimeUTC
+        $workflowDuration | Should -Be 1
+    }
+
 }