sevomin/Sevomin.Models/Ad.cs

using System;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;

namespace Sevomin.Models
{
    public class Ad
    {
        [Key]
        public long Id { get; set; }
        public string Title { get; set; }
        public string Description { get; set; }
        public int Duration { get; set; }
        public long ClickCount { get; set; }
        public string Link { get; set; }
        public DateTime CreatedDate { get; set; }
        public bool Active { get; set; }

        [NotMapped]
        public bool Expired
        {
            get { return (CreatedDate.AddDays(Duration) < DateTime.Now); }
        }
    }
}