C# Online Compiler | .NET Fiddle

using System;using System.Globalization; using System.Text.RegularExpressions;
					
public class Program
{
	public static void Main()
	{
		//Unix Stat CMD CANNOT BE FORMALIZED USING DATETIME and.or DATETIMEOFFSET FORMATS in .NET
		//                                         FFFFFFFFF  not accepted!
		
		string dateString = "2010-11-29 17:56:22.000000000 -0800"; 
		DateTimeOffset unixstatdt = new DateTimeOffset();  
        //                                                                123456789
		if (DateTimeOffset.TryParseExact(dateString, "yyyy-MM-dd HH:mm:ss.FFFFFFFFF zzz", CultureInfo.InvariantCulture, DateTimeStyles.None, out unixstatdt))
		{
				Console.WriteLine("Worked parsed Unix stat datetime with time zone\n        {0}", unixstatdt.ToString ("o"));
		}
		else
		{
			Console.WriteLine("Failed to parsed Unix stat datetime");
		}
		
		//SOLUTION 
		//WE MUST TRUNCATE THE VALUE, CRUDE BUT IT WORKS down to 7 characters from 9 
		string LinuxStatCMDpattern = @"(\d{4}-\d{2}-\d{2})\s(\d{2}:\d{2}:\d{2}\.)(\d{7})\d{2}\s ([\+-]\d{4})";
        string substitution = @"$1 $2$3 $4";
        //ACCEPTED F's of length 7 max
		//                                   FFFFFFF
		string input = @"2014-03-30 23:14:47.658210121 -0500";
        RegexOptions options = RegexOptions.Singleline | RegexOptions.IgnorePatternWhitespace;
        
		Match m = Regex.Match(input, LinuxStatCMDpattern, options); 
		Regex regex = new Regex(LinuxStatCMDpattern, options);
		
		string result = string.Empty; 
		if (m.Success) 
			result = regex.Replace(input, substitution);					          
		
		Console.WriteLine("Trimmed "  + result);

		if (DateTimeOffset.TryParseExact(result, "yyyy-MM-dd HH:mm:ss.FFFFFFF zzz", CultureInfo.InvariantCulture, DateTimeStyles.None, out unixstatdt))
		{
				Console.WriteLine("Pass 2: Worked parsed Unix stat datetime with time zone\n        {0}", unixstatdt.ToString("o"));
		}
		else
		{
			Console.WriteLine("Pass 2: Failed");
		}
		
		
	}
}

 
using System;using System.Globalization; using System.Text.RegularExpressions;
                    
public class Program
{
    public static void Main()
    {
        //Unix Stat CMD CANNOT BE FORMALIZED USING DATETIME and.or DATETIMEOFFSET FORMATS in .NET
        //                                         FFFFFFFFF  not accepted!
        
        string dateString = "2010-11-29 17:56:22.000000000 -0800"; 
        DateTimeOffset unixstatdt = new DateTimeOffset();  
        //                                                                123456789
        if (DateTimeOffset.TryParseExact(dateString, "yyyy-MM-dd HH:mm:ss.FFFFFFFFF zzz", CultureInfo.InvariantCulture, DateTimeStyles.None, out unixstatdt))
        {
                Console.WriteLine("Worked parsed Unix stat datetime with time zone\n        {0}", unixstatdt.ToString ("o"));
        }
        else
        {
            Console.WriteLine("Failed to parsed Unix stat datetime");
        }
        
        //SOLUTION 
        //WE MUST TRUNCATE THE VALUE, CRUDE BUT IT WORKS down to 7 characters from 9 
        string LinuxStatCMDpattern = @"(\d{4}-\d{2}-\d{2})\s(\d{2}:\d{2}:\d{2}\.)(\d{7})\d{2}\s ([\+-]\d{4})";