using System;

public class Program

{

    public class Revertable<T>

    {

        public readonly T DefaultValue;

        public readonly TimeSpan ResetDelay;

​

        private T _currentValue;

        private DateTimeOffset _resetTime;

​

        public Revertable(T defaultValue, TimeSpan resetDelay)

        {

            this.DefaultValue = defaultValue;

            this.ResetDelay = resetDelay;

            _resetTime = DateTimeOffset.MinValue;

            _currentValue = defaultValue;

        }

        public T Value 

        { 

            get

            {

                return (System.DateTimeOffset.Now > _resetTime)

                    ? DefaultValue 

                    : _currentValue;

            }

            set

            {

                _currentValue = value;

                _resetTime = System.DateTimeOffset.Now.Add(this.ResetDelay); 

            }

        }

    }

    public static void Main()

    {

        var r = new Revertable<string>("Default value", new TimeSpan(0,0,1));

        Console.WriteLine("Value is now {0}", r.Value);

        r.Value = "Changed";

        for (int i = 0; i<30; i++)

        {

            System.Threading.Thread.Sleep(100);

            Console.WriteLine("Value is now {0}", r.Value);

        }

    }

}