1 files changed, 29 insertions, 0 deletions
diff --git a/src/mscorlib/src/System/DateTime.CoreCLR.cs b/src/mscorlib/src/System/DateTime.CoreCLR.cs
new file mode 100644
index 0000000000..69c595663b
--- /dev/null
+++ b/src/mscorlib/src/System/DateTime.CoreCLR.cs
@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Diagnostics.Contracts;
+using System.Runtime.CompilerServices;
+
+namespace System
+{
+    public partial struct DateTime
+    {
+        public static DateTime UtcNow
+        {
+            get
+            {
+                Contract.Ensures(Contract.Result<DateTime>().Kind == DateTimeKind.Utc);
+                // following code is tuned for speed. Don't change it without running benchmark.
+                long ticks = 0;
+                ticks = GetSystemTimeAsFileTime();
+
+                return new DateTime(((UInt64)(ticks + FileTimeOffset)) | KindUtc);
+            }
+        }
+
+
+        [MethodImplAttribute(MethodImplOptions.InternalCall)]
+        internal static extern long GetSystemTimeAsFileTime();
+    }
+}