make a countdown timer

I am making a application using unity3d. In a scene ,I want to show a countdown to the users. But the countdown should stop at 6 pm (20-06-2016) .I have found a script where I can get the time difference between current time and the date I mentioned .But I can not set the time(6pm) in the date. Is there any way to get difference between current time and (6pm 20-06-2016)? and the remaining time should be in this format : hr:mm:ss .thanks in advance :slight_smile:

void Start () {
		System.DateTime datevalue1 = new System.DateTime(2016,06,07 );
		System.DateTime datevalue2 = System.DateTime.Now;
		double hours = (datevalue1 - datevalue2).TotalHours;
		Debug.Log ("It has been " + hours.ToString() + " hours since the beginning of the year");

Try using the DateTime constructor with 6 arguments: new DateTime(year, month, day, hour, minute, second). For the formatting try using the ToString options:

System.DateTime timeDifference = datevalue1 - datevalue2;
string time = timeDifference.ToString("H:mm:ss");

See here for more formatting options.