Date problem in inserting

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Data.Sql;
using System.Globalization;
using System.IO;
using Microsoft.VisualBasic;
using System.Drawing.Imaging;
namespace WindowsFormsApplication1
{

    public partial class Form1 : Form
    {
        OleDbCommand aCommand;
        OleDbConnection aConnection;
        MemoryStream ms;
        //byte[] photo_aray;
        String queryStr;
        String v_admission_no; String v_student_name;
        public Form1()
        {
            InitializeComponent();
            aConnection = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\\KVSoftware\\KVStudent\\KV1StudentInformation.mdb");

        }

        private void button1_Click(object sender, EventArgs e)
        {
            String v_admitted_class; DateTime v_admission_date;
            String v_present_class; String v_present_section; String v_roll_no; DateTime v_dob; String v_gender;
            String v_cbse_xth_roll; String v_previous_school; String v_conveyance_mode; String v_remark;
            String v_caste; String v_minority_status; String v_house;
            try
            {
                v_admission_no = textBox3.Text;
                v_student_name = textBox6.Text;
                v_admitted_class = comboBox8.SelectedItem.ToString();
                v_admission_date = dateTimePicker1.Value;
                v_present_class = comboBox9.SelectedItem.ToString();
                v_present_section = comboBox10.SelectedItem.ToString();
                v_roll_no = textBox15.Text;
                v_dob = dateTimePicker2.Value;
                Console.WriteLine(v_dob + " " + v_admission_date);
                v_cbse_xth_roll = textBox21.Text;
                v_previous_school = textBox22.Text;
                v_conveyance_mode = comboBox4.SelectedItem.ToString();
                v_remark = textBox1.Text;
                v_gender = comboBox1.SelectedItem.ToString();
                v_caste = comboBox2.SelectedItem.ToString();
                v_minority_status = comboBox7.SelectedItem.ToString();
                v_house = comboBox5.SelectedItem.ToString();
                Console.WriteLine("Check");
                aCommand = new OleDbCommand("INSERT INTO PersonalDetail(admission_no,student_name,admitted_class,admission_date,present_class,present_section,roll_no,dob,gender,caste,minority_status,house,cbse_xth_roll,previous_school,conveyance_mode,remark,photo) VALUES('" + v_admission_no + "','" + v_student_name + "','" + v_admitted_class
                   + "','" + v_admission_date+ "','" + v_present_class + "','" + v_present_section + "','" + v_roll_no + "','"
                   + v_dob+ "','" + v_gender + "','" + v_caste + "','" + v_minority_status + "','" + v_house + "','"
                   + v_cbse_xth_roll + "','" + v_previous_school + "','" + v_conveyance_mode + "','" + v_remark + "',@photo)", aConnection);
                conv_photo();
                aConnection.Open();
                int check = aCommand.ExecuteNonQuery();

                if (check == 1)
                {
                    label1.Visible = true;
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine("Error: {0}", ex.Message);
            }
        }
     
        void conv_photo()
        {
            if (pictureBox1.Image != null)
            {
                //using MemoryStream:

                ms = new MemoryStream();
                pictureBox1.Image.Save(ms, ImageFormat.Jpeg);
                byte[] photo_aray = new byte[ms.Length];
                ms.Position = 0;
                ms.Read(photo_aray, 0, photo_aray.Length);
                aCommand.Parameters.AddWithValue("@photo", photo_aray);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            openFileDialog1.Filter = "jpeg|*.jpg|bmp|*.bmp|all files|*.*";
            DialogResult res = openFileDialog1.ShowDialog();
            if (res == DialogResult.OK)
            {
                pictureBox1.Image = Image.FromFile(openFileDialog1.FileName);
            }
        }
    }
}

Table structure

Personal Detail Table
 Column Name Data Type Size Description
 admission_no text
 student_name text
 admitted_class text
 admission_date date/time
 present_class text
 present_section text
 roll_no text
 dob date/time
 gender string  
 caste string  
 minority_status yes/no
 house string  
 cbse_xth_roll text
 previous_school text
 conveyance_mode text
 remark memo
 photo ole object