From 3409bd9532177f59bf83818d8e530dc3e62634bf Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Sat, 4 Oct 2025 13:56:03 +0000
Subject: [PATCH] Fix timezone offset calculation and add tests

Co-authored-by: clayschaad <11883505+clayschaad@users.noreply.github.com>
---
 Services/ConfigurationService.cs              |  4 +-
 .../ConfigurationServiceTests.cs              | 44 +++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/Services/ConfigurationService.cs b/Services/ConfigurationService.cs
index aa2fe61..860c3ea 100644
--- a/Services/ConfigurationService.cs
+++ b/Services/ConfigurationService.cs
@@ -38,7 +38,7 @@ namespace ShiftScheduler.Services
             var startTime = TimeOnly.Parse(times[0]);
             var endTime = TimeOnly.Parse(times[1]);
             
-            TimeSpan offset = localTimeZone.GetUtcOffset(DateTime.UtcNow);
+            TimeSpan offset = localTimeZone.GetUtcOffset(date.ToDateTime(startTime));
             return (new DateTimeOffset(date, startTime, offset), new DateTimeOffset(date, endTime, offset));
         }
 
@@ -225,7 +225,7 @@ namespace ShiftScheduler.Services
             DateTimeOffset? afternoonStart = null;
             DateTimeOffset? afternoonEnd = null;
             
-            TimeSpan offset = localTimeZone.GetUtcOffset(DateTime.UtcNow);
+            TimeSpan offset = localTimeZone.GetUtcOffset(date);
             
             if (!string.IsNullOrEmpty(shift.MorningTime))
             {
diff --git a/ShiftScheduler.Services.Tests/ConfigurationServiceTests.cs b/ShiftScheduler.Services.Tests/ConfigurationServiceTests.cs
index 7470216..ef580ae 100644
--- a/ShiftScheduler.Services.Tests/ConfigurationServiceTests.cs
+++ b/ShiftScheduler.Services.Tests/ConfigurationServiceTests.cs
@@ -40,6 +40,50 @@ public class ConfigurationServiceTests
         shiftTimes.AfternoonEnd.ShouldBeNull();
     }
     
+    [Fact] 
+    public void ParseShiftTimes_WithWinterDate_ShouldUseCorrectOffset()
+    {
+        var applicationConfig = new ApplicationConfiguration();
+        var configurationService = new ConfigurationService(applicationConfig);
+        var shift = new Shift
+        {
+            MorningTime = "06:00-12:30",
+            AfternoonTime = "13:00-17:30"
+        };
+        
+        var shiftTimes = configurationService.ParseShiftTimes(DateTime.Parse("2025-11-15T13:00:00"), shift);
+        shiftTimes.MorningStart.ShouldBe(T("2025-11-15T06:00:00+01:00"));
+        shiftTimes.MorningEnd.ShouldBe(T("2025-11-15T12:30:00+01:00"));
+        shiftTimes.AfternoonStart.ShouldBe(T("2025-11-15T13:00:00+01:00"));
+        shiftTimes.AfternoonEnd.ShouldBe(T("2025-11-15T17:30:00+01:00"));
+    }
+    
+    [Fact] 
+    public void GetZurichTime_WithSummerDate_ShouldUseCorrectOffset()
+    {
+        var applicationConfig = new ApplicationConfiguration();
+        var configurationService = new ConfigurationService(applicationConfig);
+        var date = DateOnly.Parse("2025-07-13");
+        var timeRange = "06:00-12:30";
+        
+        var (startTime, endTime) = configurationService.GetZurichTime(date, timeRange);
+        startTime.ShouldBe(T("2025-07-13T06:00:00+02:00"));
+        endTime.ShouldBe(T("2025-07-13T12:30:00+02:00"));
+    }
+    
+    [Fact] 
+    public void GetZurichTime_WithWinterDate_ShouldUseCorrectOffset()
+    {
+        var applicationConfig = new ApplicationConfiguration();
+        var configurationService = new ConfigurationService(applicationConfig);
+        var date = DateOnly.Parse("2025-11-15");
+        var timeRange = "06:00-12:30";
+        
+        var (startTime, endTime) = configurationService.GetZurichTime(date, timeRange);
+        startTime.ShouldBe(T("2025-11-15T06:00:00+01:00"));
+        endTime.ShouldBe(T("2025-11-15T12:30:00+01:00"));
+    }
+    
     private DateTimeOffset T(string dateTimeString)
     {
         return DateTimeOffset.Parse(dateTimeString);