diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/DateHeaderValueManager.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/DateHeaderValueManager.cs
index b5fc6730e6..b824fb606d 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/DateHeaderValueManager.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Http/DateHeaderValueManager.cs
@@ -5,6 +5,7 @@ using System;
 using System.Text;
 using System.Threading;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
+using Microsoft.Net.Http.Headers;
 
 namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
 {
@@ -170,8 +171,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Http
         /// <param name="value">A DateTimeOffset value</param>
         private void SetDateValues(DateTimeOffset value)
         {
-            // See http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.18 for required format of Date header
-            var dateValue = value.ToString(Constants.RFC1123DateFormat);
+            var dateValue = HeaderUtilities.FormatDate(value);
             var dateBytes = new byte[_datePreambleBytes.Length + dateValue.Length];
             Buffer.BlockCopy(_datePreambleBytes, 0, dateBytes, 0, _datePreambleBytes.Length);
             Encoding.ASCII.GetBytes(dateValue, 0, dateValue.Length, dateBytes, _datePreambleBytes.Length);
diff --git a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/Constants.cs b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/Constants.cs
index 90f228de31..ddc9f767b9 100644
--- a/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/Constants.cs
+++ b/src/Microsoft.AspNetCore.Server.Kestrel/Internal/Infrastructure/Constants.cs
@@ -17,12 +17,6 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure
         /// </summary>
         public const string UnixPipeHostPrefix = "unix:/";
 
-        /// <summary>
-        /// DateTime format string for RFC1123. See  https://msdn.microsoft.com/en-us/library/az4se3k1(v=vs.110).aspx#RFC1123
-        /// for info on the format.
-        /// </summary>
-        public const string RFC1123DateFormat = "r";
-
         public const string ServerName = "Kestrel";
 
         private static int? GetEADDRINUSE()
diff --git a/test/Microsoft.AspNetCore.Server.KestrelTests/DateHeaderValueManagerTests.cs b/test/Microsoft.AspNetCore.Server.KestrelTests/DateHeaderValueManagerTests.cs
index ddfce0d3a6..8e9802600b 100644
--- a/test/Microsoft.AspNetCore.Server.KestrelTests/DateHeaderValueManagerTests.cs
+++ b/test/Microsoft.AspNetCore.Server.KestrelTests/DateHeaderValueManagerTests.cs
@@ -4,7 +4,6 @@
 using System;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Server.Kestrel.Internal.Http;
-using Microsoft.AspNetCore.Server.Kestrel.Internal.Infrastructure;
 using Microsoft.AspNetCore.Testing;
 using Xunit;
 
@@ -12,6 +11,14 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
 {
     public class DateHeaderValueManagerTests
     {
+        /// <summary>
+        /// DateTime format string for RFC1123.
+        /// </summary>
+        /// <remarks>
+        /// See https://msdn.microsoft.com/en-us/library/az4se3k1(v=vs.110).aspx#RFC1123 for info on the format.
+        /// </remarks>
+        private const string Rfc1123DateFormat = "r";
+
         [Fact]
         public void GetDateHeaderValue_ReturnsDateValueInRFC1123Format()
         {
@@ -34,7 +41,7 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 dateHeaderValueManager.Dispose();
             }
 
-            Assert.Equal(now.ToString(Constants.RFC1123DateFormat), result);
+            Assert.Equal(now.ToString(Rfc1123DateFormat), result);
         }
 
         [Fact]
@@ -63,8 +70,8 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 dateHeaderValueManager.Dispose();
             }
 
-            Assert.Equal(now.ToString(Constants.RFC1123DateFormat), result1);
-            Assert.Equal(now.ToString(Constants.RFC1123DateFormat), result2);
+            Assert.Equal(now.ToString(Rfc1123DateFormat), result1);
+            Assert.Equal(now.ToString(Rfc1123DateFormat), result2);
             Assert.Equal(1, systemClock.UtcNowCalled);
         }
 
@@ -96,8 +103,8 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
                 dateHeaderValueManager.Dispose();
             }
 
-            Assert.Equal(now.ToString(Constants.RFC1123DateFormat), result1);
-            Assert.Equal(future.ToString(Constants.RFC1123DateFormat), result2);
+            Assert.Equal(now.ToString(Rfc1123DateFormat), result1);
+            Assert.Equal(future.ToString(Rfc1123DateFormat), result2);
             Assert.True(systemClock.UtcNowCalled >= 2);
         }
 
@@ -119,8 +126,8 @@ namespace Microsoft.AspNetCore.Server.KestrelTests
             systemClock.UtcNow = future;
             var result2 = dateHeaderValueManager.GetDateHeaderValues().String;
             
-            Assert.Equal(now.ToString(Constants.RFC1123DateFormat), result1);
-            Assert.Equal(future.ToString(Constants.RFC1123DateFormat), result2);
+            Assert.Equal(now.ToString(Rfc1123DateFormat), result1);
+            Assert.Equal(future.ToString(Rfc1123DateFormat), result2);
         }
     }
 }