diff --git a/X10D/src/DateTimeExtensions.cs b/X10D/src/DateTimeExtensions.cs
deleted file mode 100644
index 871a42e..0000000
--- a/X10D/src/DateTimeExtensions.cs
+++ /dev/null
@@ -1,124 +0,0 @@
-using System;
-
-namespace X10D
-{
-    /// <summary>
-    ///     Extension methods for <see cref="DateTime" />.
-    /// </summary>
-    public static class DateTimeExtensions
-    {
-        /// <summary>
-        ///     Returns a rounded integer of the number of years since a given date as of today.
-        /// </summary>
-        /// <param name="date">The date from which to start.</param>
-        /// <returns>Returns the number of years since <paramref name="date" /> as of today.</returns>
-        public static int Age(this DateTime date)
-        {
-            return date.Age(DateTime.Today);
-        }
-
-        /// <summary>
-        ///     Returns a rounded integer of the number of years since a given date as of another given date.
-        /// </summary>
-        /// <param name="date">The date from which to start.</param>
-        /// <param name="asOf">The date at which to stop counting.</param>
-        /// <returns>
-        ///     Returns the integer number of years since <paramref name="date" /> as of
-        ///     <paramref name="asOf" />.
-        /// </returns>
-        public static int Age(this DateTime date, DateTime asOf)
-        {
-            return (int)(((asOf.Date - TimeSpan.FromDays(1) - date.Date).TotalDays + 1) / 365.2425);
-        }
-
-        /// <summary>
-        ///     Gets a DateTime representing the first occurence of a specified day in the current month.
-        /// </summary>
-        /// <param name="current">The current day.</param>
-        /// <param name="dayOfWeek">The current day of week.</param>
-        /// <returns>Returns a date representing the first occurence of <paramref name="dayOfWeek" />.</returns>
-        public static DateTime First(this DateTime current, DayOfWeek dayOfWeek)
-        {
-            var first = current.FirstDayOfMonth();
-
-            if (first.DayOfWeek != dayOfWeek)
-            {
-                first = first.Next(dayOfWeek);
-            }
-
-            return first;
-        }
-
-        /// <summary>
-        ///     Gets a <see cref="DateTime" /> representing the first day in the current month.
-        /// </summary>
-        /// <param name="current">The current date.</param>
-        /// <returns>Returns a date representing the first day of the month>.</returns>
-        public static DateTime FirstDayOfMonth(this DateTime current)
-        {
-            return current.AddDays(1 - current.Day);
-        }
-
-        /// <summary>
-        ///     Gets a <see cref="DateTime" /> representing the last specified day in the current month.
-        /// </summary>
-        /// <param name="current">The current date.</param>
-        /// <param name="dayOfWeek">The current day of week.</param>
-        /// <returns>Returns a date representing the final occurence of <paramref name="dayOfWeek" />.</returns>
-        public static DateTime Last(this DateTime current, DayOfWeek dayOfWeek)
-        {
-            var last = current.LastDayOfMonth();
-            var lastDayOfWeek = last.DayOfWeek;
-
-            var diff = dayOfWeek - lastDayOfWeek;
-            var offset = diff > 0 ? diff - 7 : diff;
-
-            return last.AddDays(offset);
-        }
-
-        /// <summary>
-        ///     Gets a <see cref="DateTime" /> representing the last day in the current month.
-        /// </summary>
-        /// <param name="current">The current date.</param>
-        /// <returns>Returns a date representing the last day of the month>.</returns>
-        public static DateTime LastDayOfMonth(this DateTime current)
-        {
-            var daysInMonth = DateTime.DaysInMonth(current.Year, current.Month);
-            return new DateTime(current.Year, current.Month, daysInMonth);
-        }
-
-        /// <summary>
-        ///     Gets a <see cref="DateTime" /> representing the first date following the current date which falls on the
-        ///     given day of the week.
-        /// </summary>
-        /// <param name="current">The current date.</param>
-        /// <param name="dayOfWeek">The day of week for the next date to get.</param>
-        /// <returns>Returns a date representing the next occurence of <paramref name="dayOfWeek" />.</returns>
-        public static DateTime Next(this DateTime current, DayOfWeek dayOfWeek)
-        {
-            var offsetDays = dayOfWeek - current.DayOfWeek;
-
-            if (offsetDays <= 0)
-            {
-                offsetDays += 7;
-            }
-
-            return current.AddDays(offsetDays);
-        }
-
-        /// <summary>
-        ///     Converts the <see cref="DateTime" /> to a Unix timestamp.
-        /// </summary>
-        /// <param name="time">The <see cref="DateTime" /> instance.</param>
-        /// <param name="useMillis">
-        ///     Optional. Whether or not the return value should be represented as milliseconds.
-        ///     Defaults to <see langword="false" />.
-        /// </param>
-        /// <returns>Returns a Unix timestamp representing the provided <see cref="DateTime" />.</returns>
-        public static long ToUnixTimeStamp(this DateTime time, bool useMillis = false)
-        {
-            DateTimeOffset offset = time;
-            return useMillis ? offset.ToUnixTimeMilliseconds() : offset.ToUnixTimeSeconds();
-        }
-    }
-}
diff --git a/X10D/src/DateTimeExtensions/DateTimeExtensions.cs b/X10D/src/DateTimeExtensions/DateTimeExtensions.cs
new file mode 100644
index 0000000..0c26c34
--- /dev/null
+++ b/X10D/src/DateTimeExtensions/DateTimeExtensions.cs
@@ -0,0 +1,76 @@
+using System;
+
+namespace X10D.DateTimeExtensions
+{
+    /// <summary>
+    ///     Extension methods for <see cref="DateTime" />.
+    /// </summary>
+    public static class DateTimeExtensions
+    {
+        /// <inheritdoc cref="DateTimeOffsetExtensions.Age(DateTimeOffset)" />
+        public static int Age(this DateTime value)
+        {
+            return value.Age(DateTime.Today);
+        }
+
+        /// <inheritdoc cref="DateTimeOffsetExtensions.Age(DateTimeOffset, DateTimeOffset)" />
+        public static int Age(this DateTime value, DateTime asOf)
+        {
+            return ((DateTimeOffset)value).Age(asOf);
+        }
+        
+        /// <inheritdoc cref="DateTimeOffsetExtensions.First(DateTimeOffset, DayOfWeek)" />
+        /// <returns>A <see cref="DateTime" /> representing the first occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTime First(this DateTime value, DayOfWeek dayOfWeek)
+        {
+            return ((DateTimeOffset)value).First(dayOfWeek).DateTime;
+        }
+
+        /// <inheritdoc cref="DateTimeOffsetExtensions.FirstDayOfMonth(DateTimeOffset)" />
+        /// <returns>A <see cref="DateTime" /> representing the first day of the current month.</returns>
+        public static DateTime FirstDayOfMonth(this DateTime value)
+        {
+            return ((DateTimeOffset)value).FirstDayOfMonth().DateTime;
+        }
+        
+        /// <inheritdoc cref="DateTimeOffsetExtensions.Last(DateTimeOffset, DayOfWeek)" />
+        /// <returns>A <see cref="DateTimeOffset" /> representing the final occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTime Last(this DateTime value, DayOfWeek dayOfWeek)
+        {
+            return ((DateTimeOffset)value).Last(dayOfWeek).DateTime;
+        }
+        /// <inheritdoc cref="DateTimeOffsetExtensions.LastDayOfMonth(DateTimeOffset)" />
+        /// <returns>A <see cref="DateTimeOffset" /> representing the last day of the current month.</returns>
+        public static DateTime LastDayOfMonth(this DateTime value)
+        {
+            return ((DateTimeOffset)value).LastDayOfMonth().DateTime;
+        }
+        
+        /// <inheritdoc cref="DateTimeOffsetExtensions.Next(DateTimeOffset, DayOfWeek)" />
+        /// <returns>A <see cref="DateTimeOffset" /> representing the next occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTime Next(this DateTime value, DayOfWeek dayOfWeek)
+        {
+            return ((DateTimeOffset)value).Next(dayOfWeek).DateTime;
+        }
+
+        /// <summary>
+        ///     Returns the number of milliseconds that have elapsed since 1970-01-01T00:00:00.000Z.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <returns>The number of milliseconds that have elapsed since 1970-01-01T00:00:00.000Z.</returns>
+        public static long ToUnixTimeMilliseconds(this DateTime value)
+        {
+            return ((DateTimeOffset)value).ToUnixTimeMilliseconds();
+        }
+
+        /// <summary>
+        ///     Returns the number of seconds that have elapsed since 1970-01-01T00:00:00.000Z.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <returns>The number of seconds that have elapsed since 1970-01-01T00:00:00.000Z.</returns>
+        public static long ToUnixTimeSeconds(this DateTime value)
+        {
+            return ((DateTimeOffset)value).ToUnixTimeSeconds();
+        }
+    }
+}
diff --git a/X10D/src/DateTimeExtensions/DateTimeOffsetExtensions.cs b/X10D/src/DateTimeExtensions/DateTimeOffsetExtensions.cs
new file mode 100644
index 0000000..92e9f32
--- /dev/null
+++ b/X10D/src/DateTimeExtensions/DateTimeOffsetExtensions.cs
@@ -0,0 +1,108 @@
+using System;
+
+namespace X10D.DateTimeExtensions
+{
+    /// <summary>
+    ///     Extension methods for <see cref="DateTimeOffset" />.
+    /// </summary>
+    public static class DateTimeOffsetExtensions
+    {
+        /// <summary>
+        ///     Returns the rounded-down integer number of years since a given date as of today.
+        /// </summary>
+        /// <param name="value">The date from which to calculate.</param>
+        /// <returns>The rounded-down integer number of years since <paramref name="value" /> as of today.</returns>
+        public static int Age(this DateTimeOffset value)
+        {
+            return value.Age(DateTime.Today);
+        }
+
+        /// <summary>
+        ///     Returns the rounded-down integer number of years since a given date as of another specified date.
+        /// </summary>
+        /// <param name="value">The date from which to calculate.</param>
+        /// <param name="asOf">The date at which to stop calculating.</param>
+        /// <returns>
+        ///     The rounded-down integer number of years since <paramref name="value" /> as of the date specified by
+        ///     <paramref name="asOf" />.
+        /// </returns>
+        public static int Age(this DateTimeOffset value, DateTimeOffset asOf)
+        {
+            return (int)(((asOf.Date - TimeSpan.FromDays(1) - value.Date).TotalDays + 1) / 365.2425);
+        }
+        
+        /// <summary>
+        ///     Gets a date representing the first occurence of a specified day of the week in the current month.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <param name="dayOfWeek">The day of the week.</param>
+        /// <returns>A <see cref="DateTimeOffset" /> representing the first occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTimeOffset First(this DateTimeOffset value, DayOfWeek dayOfWeek)
+        {
+            var first = value.FirstDayOfMonth();
+
+            if (first.DayOfWeek != dayOfWeek)
+            {
+                first = first.Next(dayOfWeek);
+            }
+
+            return first;
+        }
+
+        /// <summary>
+        ///     Gets a date representing the first day of the current month.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <returns>A <see cref="DateTimeOffset" /> representing the first day of the current month.</returns>
+        public static DateTimeOffset FirstDayOfMonth(this DateTimeOffset value)
+        {
+            return value.AddDays(1 - value.Day);
+        }
+        
+        /// <summary>
+        ///     Gets a date representing the final occurence of a specified day of the week in the current month.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <param name="dayOfWeek">The day of the week.</param>
+        /// <returns>A <see cref="DateTimeOffset" /> representing the final occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTimeOffset Last(this DateTimeOffset value, DayOfWeek dayOfWeek)
+        {
+            var last = value.LastDayOfMonth();
+            var lastDayOfWeek = last.DayOfWeek;
+
+            var diff = dayOfWeek - lastDayOfWeek;
+            var offset = diff > 0 ? diff - 7 : diff;
+
+            return last.AddDays(offset);
+        }
+
+        /// <summary>
+        ///     Gets a date representing the last day of the current month.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <returns>A <see cref="DateTimeOffset" /> representing the last day of the current month.</returns>
+        public static DateTimeOffset LastDayOfMonth(this DateTimeOffset value)
+        {
+            var daysInMonth = DateTime.DaysInMonth(value.Year, value.Month);
+            return new DateTime(value.Year, value.Month, daysInMonth);
+        }
+        
+        /// <summary>
+        ///     Gets a date representing the next occurence of a specified day of the week in the current month.
+        /// </summary>
+        /// <param name="value">The current date.</param>
+        /// <param name="dayOfWeek">The day of the week.</param>
+        /// <returns>A <see cref="DateTimeOffset" /> representing the next occurence of <paramref name="dayOfWeek" />.</returns>
+        public static DateTimeOffset Next(this DateTimeOffset value, DayOfWeek dayOfWeek)
+        {
+            var offsetDays = dayOfWeek - value.DayOfWeek;
+
+            if (offsetDays <= 0)
+            {
+                offsetDays += 7;
+            }
+
+            return value.AddDays(offsetDays);
+        }
+    }
+}