diff --git a/proto/cmp/services/accommodation/v1/info.proto b/proto/cmp/services/accommodation/v1/info.proto
index 090725f..7ebde03 100644
--- a/proto/cmp/services/accommodation/v1/info.proto
+++ b/proto/cmp/services/accommodation/v1/info.proto
@@ -13,6 +13,7 @@ message AccommodationProductInfoRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 
   // Languages
diff --git a/proto/cmp/services/accommodation/v1/list.proto b/proto/cmp/services/accommodation/v1/list.proto
index b11800a..4a3a785 100644
--- a/proto/cmp/services/accommodation/v1/list.proto
+++ b/proto/cmp/services/accommodation/v1/list.proto
@@ -11,6 +11,7 @@ message AccommodationProductListRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 }
 
diff --git a/proto/cmp/services/accommodation/v1/property_types.proto b/proto/cmp/services/accommodation/v1/property_types.proto
index af57fb1..41f2440 100644
--- a/proto/cmp/services/accommodation/v1/property_types.proto
+++ b/proto/cmp/services/accommodation/v1/property_types.proto
@@ -23,6 +23,7 @@ import "google/protobuf/timestamp.proto";
 message Property {
   // Ex: "2023-08-28T12:03:50", specifying when the static data of a product was
   // last updated
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 1;
 
   // Supplier product Code
diff --git a/proto/cmp/services/accommodation/v2/info.proto b/proto/cmp/services/accommodation/v2/info.proto
index 79ab52b..5e229a3 100644
--- a/proto/cmp/services/accommodation/v2/info.proto
+++ b/proto/cmp/services/accommodation/v2/info.proto
@@ -13,6 +13,7 @@ message AccommodationProductInfoRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 
   // Languages
diff --git a/proto/cmp/services/accommodation/v2/list.proto b/proto/cmp/services/accommodation/v2/list.proto
index 7bb7f02..f8fa569 100644
--- a/proto/cmp/services/accommodation/v2/list.proto
+++ b/proto/cmp/services/accommodation/v2/list.proto
@@ -11,6 +11,7 @@ message AccommodationProductListRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 }
 
diff --git a/proto/cmp/services/accommodation/v2/property_types.proto b/proto/cmp/services/accommodation/v2/property_types.proto
index d098ded..975779a 100644
--- a/proto/cmp/services/accommodation/v2/property_types.proto
+++ b/proto/cmp/services/accommodation/v2/property_types.proto
@@ -23,6 +23,7 @@ import "google/protobuf/timestamp.proto";
 message Property {
   // Ex: "2023-08-28T12:03:50", specifying when the static data of a product was
   // last updated
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 1;
 
   // Supplier product Code
diff --git a/proto/cmp/services/activity/v1/activity_types.proto b/proto/cmp/services/activity/v1/activity_types.proto
index 17322b5..f830b2d 100644
--- a/proto/cmp/services/activity/v1/activity_types.proto
+++ b/proto/cmp/services/activity/v1/activity_types.proto
@@ -29,6 +29,7 @@ message Activity {
 
   // Ex: "2023-08-28T12:03:50", specifying when the static data of a product was
   // last updated
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 2;
 
   // An identifier for external sessions, aiding in tracking and continuity across
@@ -90,6 +91,7 @@ message PickupDropoffEvent {
   string other_info = 4;
 
   // Datetime of the pickup dropoff event as Unix timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp date_time = 5;
 
   // Longitude and Latitude of the location
diff --git a/proto/cmp/services/activity/v1/info.proto b/proto/cmp/services/activity/v1/info.proto
index 0520c2e..94a5062 100644
--- a/proto/cmp/services/activity/v1/info.proto
+++ b/proto/cmp/services/activity/v1/info.proto
@@ -14,6 +14,7 @@ message ActivityProductInfoRequest {
 
   // Only respond with the products that are new, modified or deactivated after this
   // timestamp.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 
   // Languages to be included in the response for descriptions. Null means all
diff --git a/proto/cmp/services/activity/v1/list.proto b/proto/cmp/services/activity/v1/list.proto
index f09e455..b84a81c 100644
--- a/proto/cmp/services/activity/v1/list.proto
+++ b/proto/cmp/services/activity/v1/list.proto
@@ -11,6 +11,7 @@ message ActivityProductListRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 }
 
diff --git a/proto/cmp/services/activity/v2/activity_types.proto b/proto/cmp/services/activity/v2/activity_types.proto
index 8fb1170..35a7075 100644
--- a/proto/cmp/services/activity/v2/activity_types.proto
+++ b/proto/cmp/services/activity/v2/activity_types.proto
@@ -29,6 +29,7 @@ message Activity {
 
   // Ex: "2023-08-28T12:03:50", specifying when the static data of a product was
   // last updated
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 2;
 
   // An identifier for external sessions, aiding in tracking and continuity across
@@ -90,6 +91,7 @@ message PickupDropoffEvent {
   string other_info = 4;
 
   // Datetime of the pickup dropoff event as Unix timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp date_time = 5;
 
   // Longitude and Latitude of the location
diff --git a/proto/cmp/services/activity/v2/info.proto b/proto/cmp/services/activity/v2/info.proto
index df8c105..e230587 100644
--- a/proto/cmp/services/activity/v2/info.proto
+++ b/proto/cmp/services/activity/v2/info.proto
@@ -14,6 +14,7 @@ message ActivityProductInfoRequest {
 
   // Only respond with the products that are new, modified or deactivated after this
   // timestamp.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 
   // Languages to be included in the response for descriptions. Null means all
diff --git a/proto/cmp/services/activity/v2/list.proto b/proto/cmp/services/activity/v2/list.proto
index ac6d743..df45c7d 100644
--- a/proto/cmp/services/activity/v2/list.proto
+++ b/proto/cmp/services/activity/v2/list.proto
@@ -11,6 +11,7 @@ message ActivityProductListRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 }
 
diff --git a/proto/cmp/services/book/v1/mint.proto b/proto/cmp/services/book/v1/mint.proto
index 7a93a39..832b35e 100644
--- a/proto/cmp/services/book/v1/mint.proto
+++ b/proto/cmp/services/book/v1/mint.proto
@@ -58,6 +58,7 @@ message MintResponse {
   string provider_booking_reference = 4;
 
   // Timestamp of the booking in the inventory system of the supplier.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp provider_booking_timestamp = 5;
 
   // Price of the `BookingToken`. This field is meant to be populated by the
@@ -73,6 +74,7 @@ message MintResponse {
 
   // On chain booking token should be only buyable until this timestamp and should
   // expire after that.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp buyable_until = 9;
 
   // Transaction ID of the buy operation. This field is populated by the distributor
diff --git a/proto/cmp/services/book/v2/mint.proto b/proto/cmp/services/book/v2/mint.proto
index 2e6654d..bd10b49 100644
--- a/proto/cmp/services/book/v2/mint.proto
+++ b/proto/cmp/services/book/v2/mint.proto
@@ -57,6 +57,7 @@ message MintResponse {
   string provider_booking_reference = 4;
 
   // Timestamp of the booking in the inventory system of the supplier.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp provider_booking_timestamp = 5;
 
   // Price of the `BookingToken`. This field is meant to be populated by the
@@ -78,6 +79,7 @@ message MintResponse {
 
   // On chain booking token should be only buyable until this timestamp and should
   // expire after that.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp buyable_until = 10;
 
   // Transaction ID of the buy operation. This field is populated by the distributor
diff --git a/proto/cmp/services/info/v1/entry_requirements.proto b/proto/cmp/services/info/v1/entry_requirements.proto
index 7a496fc..a7a40be 100644
--- a/proto/cmp/services/info/v1/entry_requirements.proto
+++ b/proto/cmp/services/info/v1/entry_requirements.proto
@@ -105,6 +105,7 @@ message CountryEntryRequirementItem {
   cmp.services.info.v1.ItemStatus status = 3;
 
   // Significant update date
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_significant_update = 4;
 }
 
diff --git a/proto/cmp/services/info/v2/entry_requirements.proto b/proto/cmp/services/info/v2/entry_requirements.proto
index 28ffd09..6cdde1d 100644
--- a/proto/cmp/services/info/v2/entry_requirements.proto
+++ b/proto/cmp/services/info/v2/entry_requirements.proto
@@ -105,6 +105,7 @@ message CountryEntryRequirementItem {
   cmp.services.info.v2.ItemStatus status = 3;
 
   // Significant update date
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_significant_update = 4;
 }
 
diff --git a/proto/cmp/services/insurance/v1/info.proto b/proto/cmp/services/insurance/v1/info.proto
index 2e937b6..796a226 100644
--- a/proto/cmp/services/insurance/v1/info.proto
+++ b/proto/cmp/services/insurance/v1/info.proto
@@ -14,6 +14,7 @@ message InsuranceProductInfoRequest {
 
   // Only respond with the products that are new, modified or deactivated after this
   // timestamp.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 
   // Languages to be included in the response for descriptions. Null means all
diff --git a/proto/cmp/services/insurance/v1/insurance_types.proto b/proto/cmp/services/insurance/v1/insurance_types.proto
index c2ce976..2ceb0cc 100644
--- a/proto/cmp/services/insurance/v1/insurance_types.proto
+++ b/proto/cmp/services/insurance/v1/insurance_types.proto
@@ -38,6 +38,7 @@ message Policy {
 
   // Ex: "2023-08-28T12:03:50", specifying when the static data of a product was
   // last updated
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 3;
 }
 
diff --git a/proto/cmp/services/insurance/v1/list.proto b/proto/cmp/services/insurance/v1/list.proto
index 6212334..8bbb968 100644
--- a/proto/cmp/services/insurance/v1/list.proto
+++ b/proto/cmp/services/insurance/v1/list.proto
@@ -11,6 +11,7 @@ message InsuranceProductListRequest {
   cmp.types.v1.RequestHeader header = 1;
 
   // Only respond with the products that are modified after this timestamp
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp modified_after = 2;
 }
 
diff --git a/proto/cmp/services/ping/v1/ping.proto b/proto/cmp/services/ping/v1/ping.proto
index aac3cb3..3360525 100644
--- a/proto/cmp/services/ping/v1/ping.proto
+++ b/proto/cmp/services/ping/v1/ping.proto
@@ -17,6 +17,7 @@ message PingRequest {
   string ping_message = 2;
 
   // DateTime of the ping request
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp timestamp = 3;
 }
 
@@ -28,6 +29,7 @@ message PingResponse {
   string ping_message = 2;
 
   // DateTime of the ping response
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp timestamp = 3;
 }
 
diff --git a/proto/cmp/services/transport/v1/trip_types.proto b/proto/cmp/services/transport/v1/trip_types.proto
index b4d33a0..e212ed5 100644
--- a/proto/cmp/services/transport/v1/trip_types.proto
+++ b/proto/cmp/services/transport/v1/trip_types.proto
@@ -25,6 +25,7 @@ message Trip {
 // Represents a departure or arrival event
 message TransitEvent {
   // Date time of the event
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp date_time = 1;
 
   // Event location
diff --git a/proto/cmp/services/transport/v2/trip_types.proto b/proto/cmp/services/transport/v2/trip_types.proto
index a4fb894..82d92bb 100644
--- a/proto/cmp/services/transport/v2/trip_types.proto
+++ b/proto/cmp/services/transport/v2/trip_types.proto
@@ -25,6 +25,7 @@ message Trip {
 // Represents a departure or arrival event
 message TransitEvent {
   // Date time of the event
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp date_time = 1;
 
   // Event location
diff --git a/proto/cmp/types/v1/cancel_policy.proto b/proto/cmp/types/v1/cancel_policy.proto
index 2b43c2c..da3ee50 100644
--- a/proto/cmp/types/v1/cancel_policy.proto
+++ b/proto/cmp/types/v1/cancel_policy.proto
@@ -22,6 +22,7 @@ message CancelPolicy {
 
   // The "free cancellation upto" identifier specifies the exact DateTime upto when
   // this booking can be cancelled free of charge.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp free_cancellation_upto = 2;
 
   // Full cancellation policies can be complex and extensive. Inclusion in search
diff --git a/proto/cmp/types/v1/change_policy.proto b/proto/cmp/types/v1/change_policy.proto
index ed38f67..e81d970 100644
--- a/proto/cmp/types/v1/change_policy.proto
+++ b/proto/cmp/types/v1/change_policy.proto
@@ -21,6 +21,7 @@ message ChangePolicy {
 
   // The "free change upto" identifier specifies the exact DateTime upto when
   // this search result can be changed free of charge.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp free_change_upto = 2;
 
   // Full change policies can be complex and extensive. Inclusion in search
diff --git a/proto/cmp/types/v1/datetime_range.proto b/proto/cmp/types/v1/datetime_range.proto
index cc998ce..f1ebf40 100644
--- a/proto/cmp/types/v1/datetime_range.proto
+++ b/proto/cmp/types/v1/datetime_range.proto
@@ -10,6 +10,8 @@ import "google/protobuf/timestamp.proto";
 //
 // [Open Message Diagram](https://storage.googleapis.com/docs-cmp-files/diagrams/proto/cmp/types/v1/datetime_range.proto.dot.svg)
 message DateTimeRange {
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp start_datetime = 1;
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp end_datetime = 2;
 }
diff --git a/proto/cmp/types/v1/file.proto b/proto/cmp/types/v1/file.proto
index ca974e5..8c88600 100644
--- a/proto/cmp/types/v1/file.proto
+++ b/proto/cmp/types/v1/file.proto
@@ -15,6 +15,7 @@ message File {
   string url = 2;
 
   // Last modification time
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 3;
 }
 
diff --git a/proto/cmp/types/v2/cancel_policy.proto b/proto/cmp/types/v2/cancel_policy.proto
index 28ee10e..f69f2d1 100644
--- a/proto/cmp/types/v2/cancel_policy.proto
+++ b/proto/cmp/types/v2/cancel_policy.proto
@@ -22,6 +22,7 @@ message CancelPolicy {
 
   // The "free cancellation upto" identifier specifies the exact DateTime upto when
   // this booking can be cancelled free of charge.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp free_cancellation_upto = 2;
 
   // Full cancellation policies can be complex and extensive. Inclusion in search
diff --git a/proto/cmp/types/v2/change_policy.proto b/proto/cmp/types/v2/change_policy.proto
index baada24..bf1ff33 100644
--- a/proto/cmp/types/v2/change_policy.proto
+++ b/proto/cmp/types/v2/change_policy.proto
@@ -21,6 +21,7 @@ message ChangePolicy {
 
   // The "free change upto" identifier specifies the exact DateTime upto when
   // this search result can be changed free of charge.
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp free_change_upto = 2;
 
   // Full change policies can be complex and extensive. Inclusion in search
diff --git a/proto/cmp/types/v2/file.proto b/proto/cmp/types/v2/file.proto
index 217a163..2c6ce72 100644
--- a/proto/cmp/types/v2/file.proto
+++ b/proto/cmp/types/v2/file.proto
@@ -15,6 +15,7 @@ message File {
   string url = 2;
 
   // Last modification time
+  // For any on-chain transactions, if applicable, nanoseconds will be ignored
   google.protobuf.Timestamp last_modified = 3;
 }