diff --git a/CHANGELOG.md b/CHANGELOG.md
index eca7cd2..7fe2195 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - manipulation PhysicallyDisconnectRemovableSubsystemAfterSettingActivationStateOnOrStndBy
+- manipulation RequestIndicationOfNextCalibrationTimeRequired for devices
+- manipulation IndicateTimeOfNextCalibrationToUser for devices
 - manipulation GetComponentHwVersion for devices
 - manipulation GetAvailableDeviceMetaData for device
 - manipulation AssociateValidateAndChangeIdentificationOfPatientOrLocationContextState for contexts
diff --git a/src/t2iapi/device/service.proto b/src/t2iapi/device/service.proto
index 8bf4bcb..6a14d69 100644
--- a/src/t2iapi/device/service.proto
+++ b/src/t2iapi/device/service.proto
@@ -157,4 +157,17 @@ service DeviceService {
      */
     rpc GetComponentHwVersion (BasicHandleRequest)
         returns (t2iapi.device.GetComponentHwVersionResponse);
+
+    /*
+    Request for the given pm:AbstractDeviceComponentDescriptor handle, if it can be required by a particular standard
+    or RISK MANAGEMENT process to indicate the time of the next calibration to the USER.
+     */
+    rpc RequestIndicationOfNextCalibrationTimeRequired (BasicHandleRequest)
+        returns (BasicResponse);
+
+    /*
+    Indicate the time of the next calibration to the USER for the given pm:AbstractDeviceComponentDescriptor handle.
+     */
+    rpc IndicateTimeOfNextCalibrationToUser (BasicHandleRequest)
+        returns (BasicResponse);
 }