Domain Entity class for the Cloud Auction project

Auction.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
using SqlFu;

namespace Auction.Web.Domain.Models
{
    [Table("Auction", PrimaryKey = "Id"/*default*/, AutoGenerated = true /*default*/)]
    public class Auction : Entity<int>
    {
        public Auction(Auction auction) : base(auction.Id)
        {
            this.Title = auction.Title;
            this.Start = auction.Start;
            this.OpeningTime = auction.OpeningTime;
            this.ClosingTime = auction.ClosingTime;
            this.OpenOnSaturdays = auction.OpenOnSaturdays;
            this.OpenOnSundays = auction.OpenOnSundays;
            this.End = auction.End;
            this.Type = auction.Type;
            this.State = auction.State;
        }
        
        public Auction()
        {
        }

        [Required(ErrorMessage = "A title is required.")]
        public string Title { get; set; }

        [Required]
        public DateTime Start { get; set; }
        public DateTime? End { get; set; }

        [Display(Name = "Dagelijkse openingstijd")]
        [Required(ErrorMessage = "Dit is een verplicht veld. Vul 00:00 in als de veiling dag en nacht doorgaat")]
        [DataType(DataType.Time)]
        [DisplayFormat(DataFormatString = "{0:hh\\:mm}", ApplyFormatInEditMode = true)]
        public TimeSpan OpeningTime { get; set; }

        [Display(Name = "Dagelijkse sluitingstijd")]
        [Required(ErrorMessage = "Dit is een verplicht veld. Vul 00:00 in als de veiling dag en nacht doorgaat")]
        [DataType(DataType.Time)]
        [DisplayFormat(DataFormatString = "{0:hh\\:mm}", ApplyFormatInEditMode = true)]
        public TimeSpan ClosingTime { get; set; }

        [Display(Name = "Open op zaterdag")]
        public bool OpenOnSaturdays { get; set; }

        [Display(Name = "Open op zondag")]
        public bool OpenOnSundays { get; set; }

        [Required]
        public AuctionState State { get; set; }

        [Required]
        public AuctionType Type { get; set; }
    }


    public enum AuctionState : int
    {
        [Description("Inactive")]
        Inactive = 0,
        [Description("Planned")]
        Planned = 1,
        [Description("Running")]
        Running = 2,
        [Description("Stopped")]
        Stopped = 3,
        [Description("Finished")]
        Finished = 4
    }


    public enum AuctionType : int
    {
        [Description("Fire Sale")]
        FireSale = 0,
        [Description("Exit Auction")]
        ExitAuction = 1
    }
}