how should i create my own 'now' / DateTime.Now?
<p>i'm starting to build a part of a system which will hold a lot of DateTime validations, and a lot of 'if it was done before now' or 'if it will start in an hour etc'.</p>

<p>Usual way to go is to use <strong>DateTime.Now</strong> to get the <strong>actual time</strong>.</p>

<p>I predict however, that during unit test that will give me a real headache because i will have to setup my testdata for the time when the test will run in stead of use a default set of test data.
So i thought: why not use my own 'now' so i can set the current datetime to any moment in time.
As i don't want to set the testservers internal clock i was thinking about this solution, and i was wondering what you think of it.
Base thought is that i use my own DateTime class.
That class gives you the current datetime, but you can also set your own time from outside.</p>

<pre><code> public static class MyDateTime
    {
        private static TimeSpan _TimeDifference = TimeSpan.Zero;
        public static DateTime Now
        {
            get
            {
                return DateTime.Now + _TimeDifference;
            }
        }
        public static void SetNewNow(DateTime newNow)
        {
            _TimeDifference = newNow - DateTime.Now;
        }
        public static void AddToRealTime(TimeSpan timeSpan )
        {
            _TimeDifference =  timeSpan;
        }
        public static void SubtractFromRealTime(TimeSpan timeSpan)
        {
            _TimeDifference =  - timeSpan;
        }
    }
</code></pre>
