Pragmatic Unit Tests using "yield return" for providing test cases

using System;

namespace TestProject1
{
    /// <summary>
    /// Is used for testing
    /// </summary>
    public class ConstantTimeProvider : ITimeProvider
    {
        public ConstantTimeProvider(DateTime now)
        {
            Now = now;
        }

        #region ITimeProvider Members

        public DateTime Now { get; set; }

        #endregion
    }
}