revision date filter. allow clearing config values

src/Core/Utilities/Extensions.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Bit.Core.Utilities
+{
+    public static class Extensions
+    {
+        private const string GeneralizedTimeFormat = "yyyyMMddHHmmss.f'Z'";
+
+        public static DateTime ToDateTime(this string generalizedTimeString)
+        {
+            return DateTime.ParseExact(generalizedTimeString, GeneralizedTimeFormat, CultureInfo.InvariantCulture);
+        }
+
+        public static string ToGeneralizedTimeUTC(this DateTime date)
+        {
+            return date.ToString("yyyyMMddHHmmss.f'Z'");
+        }
+    }
+}