\xef\xbb\xbfusing System;\x0d using System.IO;\x0d \x0d namespace CodeGolf\x0d {\x0d class timeArithmetic\x0d {\x0d static void Main()\x0d {\x0d StreamReader reader = new StreamReader(Console.OpenStandardInput());\x0d string[] lines = reader.ReadToEnd().Split(new[] {Environment.NewLine}, StringSplitOptions.None);\x0d foreach (var line in lines)\x0d {\x0d string[] times = line.Split('+');\x0d DateTime t1 = DateTime.Parse(times[0]);\x0d TimeSpan t2 = TimeSpan.Parse(times[1]);\x0d DateTime t3 = t1.Add(t2);\x0d Console.WriteLine("{0:HH\\:mm\\:ss}+{1:hh\\:mm\\:ss}={2:HH\\:mm\\:ss}", t1, t2, t3);\x0d }\x0d }\x0d }\x0d }\x0d
Note that non-ascii characters in the above source code will be escaped (such as \x9f).