/// <summary>
/// 判断当前时间过了今天的百分之多少
/// </summary>
/// <returns></returns>
static double DayTimePassed()
{
  DateTime dt = DateTime.Now;
  double Numerator = dt.Hour * 60 * 60 + dt.Minute * 60 + dt.Second;
  double Denominator = 24 * 60 * 60;
  return Numerator / Denominator;
}
/// <summary>
/// 判断指定时间过了当日的百分之多少
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
static double DayTimePassed(DateTime dt)
{
  double Numerator = dt.Hour * 60 * 60 + dt.Minute * 60 + dt.Second;
  double Denominator = 24 * 60 * 60;
  return Numerator / Denominator;
}
/// <summary>
/// 判断当前时间过了今年的百分之多少
/// </summary>
/// <returns></returns>
static double YearTimePassed()
{
  DateTime dt = DateTime.Now;
  double Numerator = dt.DayOfYear * 24 * 60 * 60 +
    dt.Hour * 60 * 60 + dt.Minute * 60 + dt.Second;
  double Denominator =
    (DateTime.IsLeapYear(dt.Year) ? 366 : 365) * 24 * 60 * 60;
  return Numerator / Denominator;
}
/// <summary>
/// 判断指定时间过了当年的百分之多少
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
static double YearTimePassed(DateTime dt)
{
  double Numerator = dt.DayOfYear * 24 * 60 * 60 +
    dt.Hour * 60 * 60 + dt.Minute * 60 + dt.Second;
  double Denominator =
    (DateTime.IsLeapYear(dt.Year) ? 366 : 365) * 24 * 60 * 60;
  return Numerator / Denominator;
}

static void Main(string[] args)
{
  Console.WriteLine(DateTime.Now.ToString());
  Console.WriteLine("Day: " + DayTimePassed().ToString("P"));
  Console.WriteLine("Day: " + DayTimePassed(DateTime.Now).ToString("P"));
  Console.WriteLine("Year: " + YearTimePassed().ToString("P"));
  Console.WriteLine("Year: " + YearTimePassed(DateTime.Now).ToString("P"));
  Console.ReadLine();
}