Add DateTimeOffsetExtensions extension

Source/BSN.Commons/Extensions/DateTimeOffsetExtensions.cs

@@ -0,0 +1,30 @@
+using System;
+
+namespace BSN.Commons.Extensions
+{
+    /// <summary>
+    /// Provides extension methods for DateTimeOffset.
+    /// </summary>
+    public static class DateTimeOffsetExtensions
+    {
+        /// <summary>
+        /// Provides consistent default DateTime values across the project through centralized conversion logic.
+        /// </summary>
+        /// <remarks>
+        /// This extension method provides a standardized way to convert DateTimeOffset to DateTime:
+        /// - Maintains consistent null handling across the project
+        /// - Optimized for use in LINQ and Lambda expressions
+        /// - Ensures type-safe conversions in query projections
+        /// </remarks>
+        /// <param name="dateTimeOffset">The DateTimeOffset value to convert.</param>
+        /// <returns>A nullable DateTime equivalent.</returns>
+        public static DateTime? ToDateTimeOrDefault(this DateTimeOffset? dateTimeOffset)
+        {
+            if (dateTimeOffset.HasValue) {
+                return (DateTime?)dateTimeOffset.Value.DateTime;
+            }
+
+            return default(DateTime?);
+        }
+    }
+}