diff --git a/docs/contribute.md b/docs/contribute.md
index 56301b1d2..ff98eef14 100644
--- a/docs/contribute.md
+++ b/docs/contribute.md
@@ -1,6 +1,6 @@
 # Contributions
 
-We welcome contributions in the form of issues and pull requests. We view the contributions and the process as the same for github and external contributors.Please note the runner typically requires changes across the entire system and we aim for issues in the runner to be entirely self contained and fixable here. Therefore, we will primarily handle bug issues opened in this repo and we kindly request you to create all feature and enhancement requests on the [GitHub Feedback](https://github.com/community/community/discussions/categories/actions-and-packages) page. 
+We welcome contributions in the form of issues and pull requests. We view the contributions and the process as the same for github and external contributors. Please note the runner typically requires changes across the entire system and we aim for issues in the runner to be entirely self contained and fixable here. Therefore, we will primarily handle bug issues opened in this repo and we kindly request you to create all feature and enhancement requests on the [GitHub Feedback](https://github.com/community/community/discussions/categories/actions-and-packages) page. 
 
 > IMPORTANT: Building your own runner is critical for the dev inner loop process when contributing changes.  However, only runners built and distributed by GitHub (releases) are supported in production.  Be aware that workflows and orchestrations run service side with the runner being a remote process to run steps.  For that reason, the service can pull the runner forward so customizations can be lost.
 
diff --git a/src/Sdk/WebApi/WebApi/ResultsHttpClient.cs b/src/Sdk/WebApi/WebApi/ResultsHttpClient.cs
index d206306f5..fb250d4be 100644
--- a/src/Sdk/WebApi/WebApi/ResultsHttpClient.cs
+++ b/src/Sdk/WebApi/WebApi/ResultsHttpClient.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.IO;
 using System.Linq;
 using System.Net.Http;
@@ -132,7 +133,7 @@ namespace GitHub.Services.Results.Client
 
         private async Task StepSummaryUploadCompleteAsync(string planId, string jobId, Guid stepId, long size, CancellationToken cancellationToken)
         {
-            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat);
+            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat, CultureInfo.InvariantCulture);
             var request = new StepSummaryMetadataCreate()
             {
                 WorkflowJobRunBackendId = jobId,
@@ -148,7 +149,7 @@ namespace GitHub.Services.Results.Client
 
         private async Task StepLogUploadCompleteAsync(string planId, string jobId, Guid stepId, long lineCount, CancellationToken cancellationToken)
         {
-            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat);
+            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat, CultureInfo.InvariantCulture);
             var request = new StepLogsMetadataCreate()
             {
                 WorkflowJobRunBackendId = jobId,
@@ -164,7 +165,7 @@ namespace GitHub.Services.Results.Client
 
         private async Task JobLogUploadCompleteAsync(string planId, string jobId, long lineCount, CancellationToken cancellationToken)
         {
-            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat);
+            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat, CultureInfo.InvariantCulture);
             var request = new JobLogsMetadataCreate()
             {
                 WorkflowJobRunBackendId = jobId,
@@ -565,7 +566,7 @@ namespace GitHub.Services.Results.Client
 
         public async Task UpdateWorkflowStepsAsync(Guid planId, IEnumerable<TimelineRecord> records, CancellationToken cancellationToken)
         {
-            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat);
+            var timestamp = DateTime.UtcNow.ToString(Constants.TimestampFormat, CultureInfo.InvariantCulture);
             var stepRecords = records.Where(r => String.Equals(r.RecordType, "Task", StringComparison.Ordinal));
             var stepUpdateRequests = stepRecords.GroupBy(r => r.ParentId).Select(sg => new StepsUpdateRequest()
             {