using System;

public class Program

{

    public static void Main()

    {

         double num;

        //double.TryParse(ConfigurationManager.AppSettings["_Timer"], out num);

        DateTime currentdatetime = DateTime.Now;

        DateTime am = DateTime.Parse(DateTime.Now.ToShortDateString() + " 07:00");

        DateTime pm = DateTime.Parse(DateTime.Now.ToShortDateString() + " 19:00");

​

        if (currentdatetime > am && currentdatetime < pm)

        {

            TimeSpan ts = pm - currentdatetime;

            num = ts.TotalMilliseconds;

        }

        else if (currentdatetime > pm)

        {

            TimeSpan ts = am.AddDays(1) - currentdatetime;

            num = ts.TotalMilliseconds;

        }

        else

        {

            TimeSpan ts = am - currentdatetime;

            num = ts.TotalMilliseconds;

        }

​

       Console.WriteLine(currentdatetime.AddMilliseconds(num));

    }

}