Time Conversion

Given a time in -hour AM/PM format, convert it to military (24-hour) time.

Note: Midnight is 12:00:00AM on a 12-hour clock, and 00:00:00 on a 24-hour clock. Noon is 12:00:00PM on a 12-hour clock, and 12:00:00 on a 24-hour clock.

Solution in C# -

class Solution {

    static string timeConversion(string s) {      

        s = s.Substring(0,8)+" "+s.Substring(8);

        DateTime d = DateTime.Parse(s);

        return d.ToString("HH:mm:ss");

    }

    static void Main(string[] args) {

        TextWriter tw = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        string s = Console.ReadLine();

        string result = timeConversion(s);

        tw.WriteLine(result);

        tw.Flush();

        tw.Close();

    }

}