Random random = new Random((int)(DateTime.Now.Ticks)); int i = 0; while (i < 100) { int hour = random.Next(2, 5); int minute = random.Next(0, 60); int second = random.Next(0, 60); string tempStr = string.Format("{0} {1}:{2}:{3}", DateTime.Now.ToString("yyyy-MM-dd"), hour, minute, second); DateTime rTime = Convert.ToDateTime(tempStr); Console.WriteLine(rTime.ToString()); i++; } Console.ReadKey();