Brilliant solution, but reviewer decline it!

.gitignore

@@ -0,0 +1,188 @@
+## Ignore Visual Studio and Rider temporary files, build results, and
+## files generated by popular Visual Studio add-ons.
+
+# User-specific files
+*.suo
+*.user
+*.sln.docstates
+launchSettings.json
+
+# Build results
+
+[Dd]ebug/
+[Rr]elease/
+x64/
+build/
+[Bb]in/
+[Oo]bj/
+.vs/
+tools
+!tools/packages.config
+
+# Enable "build/" folder in the NuGet Packages folder since NuGet packages use it for MSBuild targets
+!packages/*/build/
+
+# MSTest test Results
+[Tt]est[Rr]esult*/
+[Bb]uild[Ll]og.*
+
+*_i.c
+*_p.c
+*.ilk
+*.meta
+*.obj
+*.pch
+*.pdb
+*.pgc
+*.pgd
+*.rsp
+*.sbr
+*.tlb
+*.tli
+*.tlh
+*.tmp
+*.tmp_proj
+*.log
+*.vspscc
+*.vssscc
+.builds
+*.pidb
+*.log
+*.scc
+
+# Visual C++ cache files
+ipch/
+*.aps
+*.ncb
+*.opensdf
+*.sdf
+*.cachefile
+
+# Visual Studio profiler
+*.psess
+*.vsp
+*.vspx
+
+# Guidance Automation Toolkit
+*.gpState
+
+# ReSharper is a .NET coding add-in
+_ReSharper*/
+*.[Rr]e[Ss]harper
+
+# TeamCity is a build add-in
+_TeamCity*
+
+# DotCover is a Code Coverage Tool
+*.dotCover
+
+# NCrunch
+*.ncrunch*
+.*crunch*.local.xml
+
+# Installshield output folder
+[Ee]xpress/
+
+# DocProject is a documentation generator add-in
+DocProject/buildhelp/
+DocProject/Help/*.HxT
+DocProject/Help/*.HxC
+DocProject/Help/*.hhc
+DocProject/Help/*.hhk
+DocProject/Help/*.hhp
+DocProject/Help/Html2
+DocProject/Help/html
+
+# Click-Once directory
+publish/
+
+# Publish Web Output
+*.Publish.xml
+
+# NuGet Packages Directory
+packages/
+
+# Windows Azure Build Output
+csx
+*.build.csdef
+
+# Windows Store app package directory
+AppPackages/
+
+# Rider specific folder
+\.idea/
+
+# Others
+sql/
+*.Cache
+ClientBin/
+[Ss]tyle[Cc]op.*
+~$*
+*~
+*.dbmdl
+*.[Pp]ublish.xml
+*.pfx
+*.publishsettings
+
+# RIA/Silverlight projects
+Generated_Code/
+
+# Backup & report files from converting an old project file to a newer
+# Visual Studio version. Backup files are not needed, because we have git ;-)
+_UpgradeReport_Files/
+Backup*/
+UpgradeLog*.XML
+UpgradeLog*.htm
+
+# SQL Server files
+App_Data/*.mdf
+App_Data/*.ldf
+
+
+#LightSwitch generated files
+GeneratedArtifacts/
+_Pvt_Extensions/
+ModelManifest.xml
+
+# =========================
+# Windows detritus
+# =========================
+
+# Windows image file caches
+Thumbs.db
+ehthumbs.db
+
+# Folder config file
+Desktop.ini
+
+# Recycle Bin used on file shares
+$RECYCLE.BIN/
+
+# Mac desktop service store files
+.DS_Store
+
+# =========================
+# NUnit Specific
+# =========================
+
+.~
+*.userprefs
+*.StyleCop
+*.sdf
+GeneratedAssemblyInfo.cs
+StyleCop.Cache
+local.settings.include
+InternalTrace.txt
+TestResult.xml
+testCaseCollection.xml
+deploy
+lib
+test-results
+package
+images
+MockAssemblyResult.xml
+PortabilityAnalysis*.html
+project.lock.json
+*.project.lock.json
+.dotnet
+.config/dotnet-tools.json

BDD/BerlinClockFeatureSteps.cs

@@ -1,28 +1,27 @@
-using System;
-using TechTalk.SpecFlow;
+using BerlinClock.Interfaces;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
-using System.Linq;
+using TechTalk.SpecFlow;
 
 namespace BerlinClock
 {
-    [Binding]
-    public class TheBerlinClockSteps
-    {
-        private ITimeConverter berlinClock = new TimeConverter();
-        private String theTime;
+	[Binding]
+	public class TheBerlinClockSteps
+	{
+		private ITimeConverter berlinClock = new BerlinClockTimeConverter();
+		private string theTime;
+
+
+		[When(@"the time is ""(.*)""")]
+		public void WhenTheTimeIs(string time)
+		{
+			this.theTime = time;
+		}
 
-
-        [When(@"the time is ""(.*)""")]
-        public void WhenTheTimeIs(string time)
-        {
-            theTime = time;
-        }
-
-        [Then(@"the clock should look like")]
-        public void ThenTheClockShouldLookLike(string theExpectedBerlinClockOutput)
-        {
-            Assert.AreEqual(berlinClock.convertTime(theTime), theExpectedBerlinClockOutput);
-        }
+		[Then(@"the clock should look like")]
+		public void ThenTheClockShouldLookLike(string theExpectedBerlinClockOutput)
+		{
+			Assert.AreEqual(this.berlinClock.ConvertTime(this.theTime), theExpectedBerlinClockOutput);
+		}
 
-    }
+	}
 }

BerlinClock.csproj

@@ -50,14 +50,18 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="BDD\BerlinClockFeatureSteps.cs" />
+    <Compile Include="Classes\Utils\StringHelper.cs" />
+    <Compile Include="Interfaces\Clock\BerlinClockModel.cs" />
+    <Compile Include="Classes\Clock\ViewFormats\BerlinClockCharViewFormat.cs" />
+    <Compile Include="Interfaces\Clock\ViewFormats\IBerlinClockViewFormat.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="BDD\BerlinClockFeatureSteps.feature.cs">
       <AutoGen>True</AutoGen>
       <DesignTime>True</DesignTime>
       <DependentUpon>BerlinClockFeatureSteps.feature</DependentUpon>
     </Compile>
-    <Compile Include="Classes\ITimeConverter.cs" />
-    <Compile Include="Classes\TimeConverter.cs" />
+    <Compile Include="Interfaces\ITimeConverter.cs" />
+    <Compile Include="Classes\BerlinClockTimeConverter.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
@@ -70,6 +74,7 @@
   <ItemGroup>
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
+  <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.

BerlinClock.sln

@@ -1,10 +1,12 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2013
-VisualStudioVersion = 12.0.21005.1
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29806.167
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "BerlinClock", "BerlinClock.csproj", "{0451204D-BF86-43E1-B560-FC9AC830B9A9}"
 EndProject
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "BerlinClockNUnitTest", "BerlinClockNUnitTest\BerlinClockNUnitTest.csproj", "{69310066-B9EC-4A1F-85E2-E1F6D8F015ED}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -15,8 +17,15 @@ Global
 		{0451204D-BF86-43E1-B560-FC9AC830B9A9}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{0451204D-BF86-43E1-B560-FC9AC830B9A9}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{0451204D-BF86-43E1-B560-FC9AC830B9A9}.Release|Any CPU.Build.0 = Release|Any CPU
+		{69310066-B9EC-4A1F-85E2-E1F6D8F015ED}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{69310066-B9EC-4A1F-85E2-E1F6D8F015ED}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{69310066-B9EC-4A1F-85E2-E1F6D8F015ED}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{69310066-B9EC-4A1F-85E2-E1F6D8F015ED}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
 	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {E8033423-7F55-436F-96A2-24BE7E6C8B42}
+	EndGlobalSection
 EndGlobal

BerlinClockNUnitTest/BerlinClockNUnitTest.csproj

@@ -0,0 +1,19 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="nunit" Version="3.12.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="3.15.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.4.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\BerlinClock.csproj" />
+  </ItemGroup>
+
+</Project>