diff --git a/lib/ExpressionDescriptor.cs b/lib/ExpressionDescriptor.cs
index e770b254..385143a6 100644
--- a/lib/ExpressionDescriptor.cs
+++ b/lib/ExpressionDescriptor.cs
@@ -12,7 +12,7 @@ namespace CronExpressionDescriptor
   public class ExpressionDescriptor
   {
     private readonly char[] m_specialCharacters = new char[] { '/', '-', ',', '*' };
-    private readonly string[] m_24hourTimeFormatTwoLetterISOLanguageName = new string[] { "ru", "uk", "de", "it", "tr", "pl", "ro", "da", "sl", "fi", "sv", "nb", "hu" };
+    private readonly string[] m_24hourTimeFormatTwoLetterISOLanguageName = new string[] { "ru", "uk", "de", "it", "tr", "pl", "ro", "da", "sl", "fi", "sv", "nb", "hu", "cs" };
 
     private string m_expression;
     private Options m_options;