diff --git a/IoTCIntegration/index.js b/IoTCIntegration/index.js
index 426ae92..c7697ad 100644
--- a/IoTCIntegration/index.js
+++ b/IoTCIntegration/index.js
@@ -18,7 +18,7 @@ let kvToken;
 
 module.exports = async function (context, req) {
     try {
-        await handleMessage({ ...parameters, log: context.log, getSecret: getKeyVaultSecret }, req.body.device, req.body.measurements);
+        await handleMessage({ ...parameters, log: context.log, getSecret: getKeyVaultSecret }, req.body.device, req.body.measurements, req.body.timestamp);
     } catch (e) {
         context.log('[ERROR]', e.message);
 
diff --git a/IoTCIntegration/lib/engine.js b/IoTCIntegration/lib/engine.js
index 37ff64e..489ff65 100644
--- a/IoTCIntegration/lib/engine.js
+++ b/IoTCIntegration/lib/engine.js
@@ -26,7 +26,7 @@ const deviceCache = {};
  * @param {{ deviceId: string }} device 
  * @param {{ [field: string]: number }} measurements 
  */
-module.exports = async function (context, device, measurements) {
+module.exports = async function (context, device, measurements, timestamp) {
     if (device) {
         if (!device.deviceId || !/^[a-z0-9\-]+$/.test(device.deviceId)) {
             throw new StatusError('Invalid format: deviceId must be alphanumeric, lowercase, and may contain hyphens.', 400);
@@ -39,12 +39,22 @@ module.exports = async function (context, device, measurements) {
         throw new StatusError('Invalid format: invalid measurement list.', 400);
     }
 
+    if (timestamp && isNaN(Date.parse(timestamp))) {
+        throw new StatusError('Invalid format: if present, timestamp must be in ISO format (e.g., YYYY-MM-DDTHH:mm:ss.sssZ)', 400);
+    }
+
     const client = Device.Client.fromConnectionString(await getDeviceConnectionString(context, device), DeviceTransport.Http);
 
     try {
+        const message = new Device.Message(JSON.stringify(measurements));
+
+        if (timestamp) {
+            message.properties.add('iothub-creation-time-utc', timestamp);
+        }
+
         await util.promisify(client.open.bind(client))();
         context.log('[HTTP] Sending telemetry for device', device.deviceId);
-        await util.promisify(client.sendEvent.bind(client))(new Device.Message(JSON.stringify(measurements)));
+        await util.promisify(client.sendEvent.bind(client))(message);
         await util.promisify(client.close.bind(client))();
     } catch (e) {
         // If the device was deleted, we remove its cached connection string
diff --git a/README.md b/README.md
index fe03c74..7692e1a 100644
--- a/README.md
+++ b/README.md
@@ -34,7 +34,7 @@ In the console, run the command `npm install` (this command takes ~20 minutes to
 
 ![Get function URL](assets/getFunctionUrl.PNG "Get function URL")
 
-Messages sent to the device bridge must have the following format in the Body:
+Messages sent to the device bridge must have the following format in the body:
 ```json
 {
     "device": {
@@ -49,6 +49,10 @@ Messages sent to the device bridge must have the following format in the Body:
 }
 ```
 
+An optional `timestamp` field can be included in the body, to specify the UTC date and time of the message.
+This field must be in ISO format (e.g., YYYY-MM-DDTHH:mm:ss.sssZ). If `timestamp` is not provided,
+the current date and time will be used.
+
 > NOTE: `deviceId` must be alphanumeric, lowercase, and may contain hyphens. The values of the fields in `measurements` must be numbers or strings.
 
 6. When a message with a new `deviceId` is sent to IoT Central by the device bridge, a device will be created as an **Unassociated device**. Unassociated devices appear in your IoT Central application in `Device Explorer > Unassociated devices`. Click `Associate` and choose a device template to start receiving incoming measurements from that device in IoT Central.
@@ -246,7 +250,7 @@ Function. You can check the integrity of the code being deployed by verifying th
 of the `iotc-bridge-az-function.zip` file in the root of this repository matches the following:
 
 ```
-A55889E1808D666CE03A2A32C2B304F4DADAA6F72D599CA0D4A15C8666737E4F
+4DE7C133828461E5C2E11125E7B22E12AA4E238BF19F4837E0D16950109DAF68
 ```
 
 # Contributing
diff --git a/iotc-bridge-az-function.zip b/iotc-bridge-az-function.zip
index 121dbe5..fe8ad59 100644
Binary files a/iotc-bridge-az-function.zip and b/iotc-bridge-az-function.zip differ