NHibernate UnixTime UserType

UnixTimeType.cs

using System;
using System.Data;
using NHibernate.SqlTypes;
using NHibernate.Util;

namespace NHibernate.UserTypes
{
    public class UnixTimeType : IUserType
    {
        public System.Type ReturnedType => typeof(DateTimeOffset);

        public SqlType[] SqlTypes => new[] { SqlTypeFactory.Int64 };

        public object Assemble(object cached, object owner)
        {
            return cached;
        }

        public object DeepCopy(object value)
        {
            if (value == null) return null;
            var date = (DateTimeOffset)value;
            return new DateTimeOffset(date.Ticks, date.Offset);
        }

        public object Disassemble(object value)
        {
            return value;
        }

        public new bool Equals(object x, object y)
        {
            return EqualsHelper.Equals(x, y);
        }

        public int GetHashCode(object x)
        {
            return x.GetHashCode();
        }

        public bool IsMutable
        {
            get { return false; }
        }

        public object NullSafeGet(IDataReader rs, string[] names, object owner)
        {
            var value = NHibernateUtil.Double.NullSafeGet(rs, names[0]);
            var unitTime = Convert.ToInt64(value);
            return DateTimeOffset.FromUnixTimeSeconds(unitTime);
        }

        public void NullSafeSet(IDbCommand cmd, object value, int index)
        {
            if (value == null)
            {
                NHibernateUtil.Int64.NullSafeSet(cmd, null, index);
                return;
            }
            var date = (DateTimeOffset)value;
            var unixTime = date.ToUnixTimeSeconds();
            NHibernateUtil.Int64.NullSafeSet(cmd, unixTime, index);
        }

        public object Replace(object original, object target, object owner)
        {
            return original;
        }
    }
}