diff --git a/README.md b/README.md
index b8a8355..2c28799 100644
--- a/README.md
+++ b/README.md
@@ -46,4 +46,7 @@
 |  1  | 0x1200  |  √   |  主链路动态信息交换消息  |
 |  2  | 0x1201  |  √   |  上传车辆注册信息  |
 |  3  | 0x1202  |  √   |  实时上传车辆定位信息  |
-|  4  | 0x1203  |  √   |  车辆定位信息自动补报  |
\ No newline at end of file
+|  4  | 0x1203  |  √   |  车辆定位信息自动补报  |
+|  5  | 0x1205  |  √   |  启动车辆定位信息交换应答消息  |
+|  6  | 0x1206  |  √   |  结束车辆定位信息交换应答消息  |
+|  7  | 0x1207  |  √   |  申请交换指定车辆定位信息请求消息  |
\ No newline at end of file
diff --git a/doc/808809补充协议.pdf b/doc/808809补充协议.pdf
index 70c7584..0e7ccc5 100644
Binary files a/doc/808809补充协议.pdf and b/doc/808809补充协议.pdf differ
diff --git a/src/JT809.Protocol.Test/JT809SubMessageBody/JT809_0x1200_0x1207Test.cs b/src/JT809.Protocol.Test/JT809SubMessageBody/JT809_0x1200_0x1207Test.cs
new file mode 100644
index 0000000..7d13e3d
--- /dev/null
+++ b/src/JT809.Protocol.Test/JT809SubMessageBody/JT809_0x1200_0x1207Test.cs
@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using Xunit;
+using JT809.Protocol;
+using JT809.Protocol.JT809Extensions;
+using JT809.Protocol.JT809MessageBody;
+using JT809.Protocol.JT809Exceptions;
+using JT809.Protocol.JT809SubMessageBody;
+
+namespace JT809.Protocol.Test.JT809SubMessageBody
+{
+    public class JT809_0x1200_0x1207Test
+    {
+        [Fact]
+        public void Test1()
+        {
+            JT809_0x1200_0x1207 jT809_0X1200_0X1201 = new JT809_0x1200_0x1207
+            {
+                StartTime = DateTime.Parse("2018-09-24 14:14:14"),
+                EndTime = DateTime.Parse("2018-09-24 23:23:23")
+            };
+            var hex = JT809Serializer.Serialize(jT809_0X1200_0X1201).ToHexString();
+            //"00 00 00 00 5B A8 80 B6 00 00 00 00 5B A9 01 6B"
+        }
+
+        [Fact]
+        public void Test2()
+        {
+            var bytes = "00 00 00 00 5B A8 80 B6 00 00 00 00 5B A9 01 6B".ToHexBytes();
+            JT809_0x1200_0x1207 jT809_0X1200_0X1201 = JT809Serializer.Deserialize<JT809_0x1200_0x1207>(bytes);
+            Assert.Equal(DateTime.Parse("2018-09-24 14:14:14"), jT809_0X1200_0X1201.StartTime);
+            Assert.Equal(DateTime.Parse("2018-09-24 23:23:23"), jT809_0X1200_0X1201.EndTime);
+        }
+    }
+}
diff --git a/src/JT809.Protocol/JT809Enums/JT809SubBusinessType.cs b/src/JT809.Protocol/JT809Enums/JT809SubBusinessType.cs
index 5fa67da..2d67fc8 100644
--- a/src/JT809.Protocol/JT809Enums/JT809SubBusinessType.cs
+++ b/src/JT809.Protocol/JT809Enums/JT809SubBusinessType.cs
@@ -32,16 +32,19 @@ namespace JT809.Protocol.JT809Enums
         ///启动车辆定位信息交换应答	
         ///</summary>
         [Description("启动车辆定位信息交换应答")]
+        [JT809BodiesType(typeof(JT809_0x1200_0x1205))]
         UP_EXG_MSG_RETURN_STARTUP_ACK = 0x1205,
         ///<summary>
         ///结束车辆定位信息交换应答	
         ///</summary>
         [Description("结束车辆定位信息交换应答")]
+        [JT809BodiesType(typeof(JT809_0x1200_0x1206))]
         UP_EXG_MSG_RETURN_END_ACK = 0x1206,
         ///<summary>
         ///申请交换指定车辆定位信息请求	
         ///</summary>
         [Description("申请交换指定车辆定位信息请求")]
+        [JT809BodiesType(typeof(JT809_0x1200_0x1207))]
         UP_EXG_MSG_APPLY_FOR_MONITOR_STARTUP = 0x1207,
         ///<summary>
         ///取消交换指定车辆定位信息请求	
diff --git a/src/JT809.Protocol/JT809Extensions/JT809BinaryExtensions.cs b/src/JT809.Protocol/JT809Extensions/JT809BinaryExtensions.cs
index d6a4cc6..a5177d3 100644
--- a/src/JT809.Protocol/JT809Extensions/JT809BinaryExtensions.cs
+++ b/src/JT809.Protocol/JT809Extensions/JT809BinaryExtensions.cs
@@ -18,6 +18,8 @@ namespace JT809.Protocol.JT809Extensions
 
         private static ulong[] CRC = new ulong[256]; //建立CRC16表 
 
+        private static readonly DateTime UTCBaseTime = new DateTime(1970, 1, 1);
+
         static JT809BinaryExtensions()
         {
             Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
@@ -117,6 +119,18 @@ namespace JT809.Protocol.JT809Extensions
             return dateTime;
         }
 
+        public static DateTime ReadUTCDateTimeLittle(ReadOnlySpan<byte> buf, ref int offset)
+        {
+            ulong result = 0;
+            for (int i = 0; i < 8; i++)
+            {
+                ulong currentData = (ulong)buf[offset+i] << (8 * (8 - i - 1));
+                result += currentData;
+            }
+            offset += 8;
+            return UTCBaseTime.AddSeconds(result).AddHours(8);
+        }
+
         public static int ReadInt32Little(ReadOnlySpan<byte> read, ref int offset)
         {
             int value = (read[offset] << 24) | (read[offset + 1] << 16) | (read[offset + 2] << 8) | read[offset + 3];
@@ -367,6 +381,18 @@ namespace JT809.Protocol.JT809Extensions
             return len;
         }
 
+        public static int WriteUTCDateTimeLittle(IMemoryOwner<byte> memoryOwner, int offset, DateTime date)
+        {
+            ulong totalSecends = (ulong)(date.AddHours(-8) - UTCBaseTime).TotalSeconds;
+            //高位在前
+            for (int i = 7; i >= 0; i--)
+            {
+                memoryOwner.Memory.Span[offset+i] = (byte)(totalSecends & 0xFF);  //取低8位
+                totalSecends = totalSecends >> 8;
+            }
+            return 8;
+        }
+
         public static IEnumerable<byte> ToBytes(this string data, Encoding coding)
         {
             return coding.GetBytes(data);
diff --git a/src/JT809.Protocol/JT809Formatters/JT809SubMessageBodyFormatters/JT809_0x1200_0x1207Formatter.cs b/src/JT809.Protocol/JT809Formatters/JT809SubMessageBodyFormatters/JT809_0x1200_0x1207Formatter.cs
new file mode 100644
index 0000000..2c489c0
--- /dev/null
+++ b/src/JT809.Protocol/JT809Formatters/JT809SubMessageBodyFormatters/JT809_0x1200_0x1207Formatter.cs
@@ -0,0 +1,29 @@
+using JT809.Protocol.JT809Extensions;
+using JT809.Protocol.JT809SubMessageBody;
+using System;
+using System.Buffers;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JT809.Protocol.JT809Formatters.JT809SubMessageBodyFormatters
+{
+    public class JT809_0x1200_0x1207Formatter : IJT809Formatter<JT809_0x1200_0x1207>
+    {
+        public JT809_0x1200_0x1207 Deserialize(ReadOnlySpan<byte> bytes, out int readSize)
+        {
+            int offset = 0;
+            JT809_0x1200_0x1207 jT809_0X1200_0X1207 = new JT809_0x1200_0x1207();
+            jT809_0X1200_0X1207.StartTime = JT809BinaryExtensions.ReadUTCDateTimeLittle(bytes, ref offset);
+            jT809_0X1200_0X1207.EndTime = JT809BinaryExtensions.ReadUTCDateTimeLittle(bytes, ref offset);
+            readSize = offset;
+            return jT809_0X1200_0X1207;
+        }
+
+        public int Serialize(IMemoryOwner<byte> memoryOwner, int offset, JT809_0x1200_0x1207 value)
+        {
+            offset += JT809BinaryExtensions.WriteUTCDateTimeLittle(memoryOwner, offset, value.StartTime);
+            offset += JT809BinaryExtensions.WriteUTCDateTimeLittle(memoryOwner, offset, value.EndTime);
+            return offset;
+        }
+    }
+}
diff --git a/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1205.cs b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1205.cs
new file mode 100644
index 0000000..a846a94
--- /dev/null
+++ b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1205.cs
@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JT809.Protocol.JT809SubMessageBody
+{
+    /// <summary>
+    /// 启动车辆定位信息交换应答消息
+    /// <para>子业务类型标识:UP_EXG_ MSG_ RETURN_ STARTUP ACK</para>
+    /// <para>描述：本条消息是下级平台对上级平台下发的 DOWN_EXG_ MSG_ RETURN_STARTUP 消息的应答消息</para>
+    /// </summary>
+    public class JT809_0x1200_0x1205:JT809SubBodies
+    {
+
+    }
+}
diff --git a/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1206.cs b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1206.cs
new file mode 100644
index 0000000..86fa0a0
--- /dev/null
+++ b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1206.cs
@@ -0,0 +1,14 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JT809.Protocol.JT809SubMessageBody
+{
+    /// <summary>
+    /// 结束车辆定位信息交换应答消息
+    /// <para>子业务类型标识:UP_EXG_MSG_RETURN_END_ACK</para>
+    /// </summary>
+    public class JT809_0x1200_0x1206:JT809SubBodies
+    {
+    }
+}
diff --git a/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1207.cs b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1207.cs
new file mode 100644
index 0000000..f484eb0
--- /dev/null
+++ b/src/JT809.Protocol/JT809SubMessageBody/JT809_0x1200_0x1207.cs
@@ -0,0 +1,26 @@
+using JT809.Protocol.JT809Attributes;
+using JT809.Protocol.JT809Formatters.JT809SubMessageBodyFormatters;
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace JT809.Protocol.JT809SubMessageBody
+{
+    /// <summary>
+    /// 申请交换指定车辆定位信息请求消息
+    /// <para>子业务类型标识:UP_EXG_MSG_APPLY-FOR_MONITOR_STARTUP</para>
+    /// <para>描述:当下级平台需要在特定时问段内监控特殊车辆时，可上传此命令到上级平台申请对该车辆定位数据交换到下级平台，申请成功后，此车辆定位数据将在指定时间内交换到该平台(即使该车没有进入该平台所属区域也会交换)</para>
+    /// </summary>
+    [JT809Formatter(typeof(JT809_0x1200_0x1207Formatter))]
+    public class JT809_0x1200_0x1207:JT809SubBodies
+    {
+        /// <summary>
+        /// 开始时间，用 UTC 时间表示
+        /// </summary>
+        public DateTime StartTime { get; set; }
+        /// <summary>
+        /// 结束时间，用 UTC 时间表示
+        /// </summary>
+        public DateTime EndTime { get; set; }
+    }
+}