TOOL-Converting JSON DateTime String to .NET DateTime Structure

using System;

using System.Text.RegularExpressions;

using System.IO;

using System.Text;

namespace Darkthread

{

    class Program

    {

        //getTime() in Javascript is milliseconds since January 1, 1970

        //Ticks in .NET is nanoseconds since January 1, 0000

        //new DateTime(1970, 1, 1).Ticks = 621355968000000000

        static long baseTicks = 621355968000000000;

        //Convert Javascript ticks to DateTime

        static string GetDateTimeString(long jsTicks, int utcDiff = 0)

        {

            return new DateTime(jsTicks * 10000 + baseTicks).AddHours(utcDiff)

                       .ToString("yyyy/MM/ddTHH:mm:ssZ");

        }

        //Convert JSON date string to DateTime

        static string GetDateTimeString(string jsonDateString)

        {

            int p = jsonDateString.IndexOf("(") + 1;

            string numStr = jsonDateString.Substring(p,

                    jsonDateString.IndexOf(")") - p

                );

            int utcDiff = 0;

            string[] a = numStr.Split('+', '-');

            if (a.Length == 2)

            {

                utcDiff = (numStr.Contains("-") ? -1 : 1) * 

                    int.Parse(a[1].Substring(0, 2));

                numStr = a[0];

            }

            return GetDateTimeString(long.Parse(numStr), utcDiff);

        }

        static void Main(string[] args)

        {

            if (args.Length < 1 || args.Length > 2)

            {

                Console.WriteLine("Syntax: ConvJsonDate file_name or " +

                                  "ConvJsonDate file_name_*.ext output_path");

                return;

            }

            string fn = args[0];

            string[] files = new string[] { fn };

            //for wildcard search

            if (fn.Contains("*"))

            {

                string srcFolder = Path.GetDirectoryName(fn);

                //if no path assigned, use current folder

                if (string.IsNullOrEmpty(srcFolder))

                    srcFolder = ".";

                string pattern = Path.GetFileName(fn);

                files = Directory.GetFiles(srcFolder, pattern);

            }

            //get output path if assigned

            string path = args.Length > 1 ? args[1] : null;

            //define regular expression pattern

            Regex re = new Regex(@"\\/Date\([0-9+-]+\)\\/");

            StringBuilder sb = new StringBuilder();

            foreach (string f in files)

            {

                using (StreamReader sr = new StreamReader(f))

                {

                    string line;

                    sb.Length = 0;

                    while ((line = sr.ReadLine()) != null)

                        //convert \/Date(....)\/ to yyyy-MM-ddTHH:mm:ssZ

                        sb.AppendLine(

                            re.Replace(line, (o) => GetDateTimeString(o.Value)));

                    if (string.IsNullOrEmpty(path))

                        //if no path assigned, output the converted text to console

                        Console.Write(sb.ToString());

                    else

                        //if path is assigned, dump the converted text to files

                        try

                        {

                            File.WriteAllText(Path.Combine(path, Path.GetFileName(f)), 

                                sb.ToString());

                        }

                        catch (Exception ex)

                        {

                            Console.WriteLine(ex.Message);

                            return;

                        }

                }

            }

        }

    }

}