object date-time conversion to to-String in ASP.NET MVC5 -

hi developing own project in asp.net mvc5 getting error when using insert command , writing query in 'string.format' , error 'an exception of type 'system.data.sqlclient.sqlexception' occurred in system.data.dll not handled in user code

additional information: conversion of varchar data type datetime data type resulted in out-of-range value.

the statement has been terminated.'

and code is

`public void addcar(car obj)

    {          string strconn = "server = amarnath\\server; database = carparking; integrated security = true;";          string cmdtext = string.format("insert car(parking_id, car_no, mobile_no, starting_time, ending_time, total_time, charges) values({0}, '{1}', {2}, '{3}', '{4}', '{5}', '{6}');" + "select @@identity",             obj.parking_id, obj.car_no, obj.mobile_no, obj.starting_time.tostring(), obj.ending_time.tostring(), obj.total_time, obj.charges);          sqlconnection conn = new sqlconnection(strconn);         sqlcommand cmd = new sqlcommand(cmdtext, conn);          conn.open();         cmd.executenonquery();         conn.close();     }` 

and want know best way write query in string.format or parameterised