Stubbable replacement for DateTime.Now

SystemClock.cs

public static class SystemClock 
{
    static SystemClock()
    {
        Live();
    }

    public static DateTime Now
    {
        get { return _getTime(); }
    }
        
    public static void Live()
    {
        _getTime = () => DateTime.UtcNow;
    }

    public static void Stub(DateTime theTimeToReturn)
    {
        _getTime = () => theTimeToReturn;
    }

    public static DateTime Today { get { return _getTime().Date; } }

    public static void Stub(Func<DateTime> getTime)
    {
        _getTime = getTime;
    }

    private static Func<DateTime> _getTime;
}