Javascript Date To C# Webservice Error -

i been trying convert javascript date c# datetime format inserted microsoft sql database.

this codes have:

javascript side:

var     = new date(); =  now.toutcstring(); 

c# side:

//time variable in datetime format  console.writeline("before: "+time); string timestring = convert.tostring(time);  console.writeline("convert: "+timestring);  datetime newdt =  datetime.parseexact(timestring, "yyyy-mm-dd hh:mm:ss:fff",   cultureinfo.invariantculture);  console.writeline("after: "+newdt); 

error msg:

system.formatexception: string not recognized valid datetime. @ system.datetimeparse.parseexact(string s, string format,    datetimeformatinfo dtfi, datetimestyles style) @ -classfile&method name omiited-(datetime time) 

debug info:

 before: 17/8/2015 11:43:48  convert: 17/8/2015 11:43:48 

i'm pretty sure "timestring" inside parseexact wrong.

any ideas on how solve ? format of result want in format: 2015-07-27 14:24:23.853 . thanks!

17/8/2015 11:43:48 am against format dd/m/yyyy hh:mm:ss tt,and use tostring format

datetime newdt = datetime.parseexact(timestring, "dd/m/yyyy hh:mm:ss tt", cultureinfo.invariantculture); console.writeline("after: "+newdt.tostring("yyyy-mm-dd hh:mm:ss.fff"));