diff --git a/API.md b/API.md
index d5f195db..889e5001 100644
--- a/API.md
+++ b/API.md
@@ -1260,8 +1260,8 @@ curl http://localhost:<port>/irods-http-api/<version>/data-objects \
     --data-urlencode 'replica-number=<integer>' \
     --data-urlencode 'new-data-checksum=<string>' \
     --data-urlencode 'new-data-comments=<string>' \
-    --data-urlencode 'new-data-create-time=<integer>' \
-    --data-urlencode 'new-data-expiry=<integer>' \
+    --data-urlencode 'new-data-create-time=<string>' \
+    --data-urlencode 'new-data-expiry-time=<string>' \
     --data-urlencode 'new-data-mode=<string>' \
     --data-urlencode 'new-data-modify-time=<string>' \
     --data-urlencode 'new-data-path=<string>' \
@@ -1272,11 +1272,17 @@ curl http://localhost:<port>/irods-http-api/<version>/data-objects \
     --data-urlencode 'new-data-status=<string>' \
     --data-urlencode 'new-data-type-name=<string>' \
     --data-urlencode 'new-data-version=<string>' \
-    --data-urlencode 'new-data-access-time=<string>' # Must be 11 bytes in length and padded with leading zeros.
+    --data-urlencode 'new-data-access-time=<string>'
 ```
 
 `resource-hierarchy` and `replica-number` are mutually exclusive parameters.
 
+The following parameters must be 11 bytes in length and padded with leading zeros.
+- `new-data-access-time`
+- `new-data-create-time`
+- `new-data-expiry-time`
+- `new-data-modify-time`
+
 `new-data-access-time` is supported by iRODS 5 only. Attempting to modify this property while connected to an iRODS server earlier than 5.0.0 will result in an HTTP status code of 400.
 
 All parameters having a prefix of `new-` represent modifiable properties of the target replica. At least one modifiable property is required for the operation to succeed. This operation allows multiple properties to be modified in a single call.
diff --git a/endpoints/data_objects/src/main.cpp b/endpoints/data_objects/src/main.cpp
index 0c0cb447..7eccc821 100644
--- a/endpoints/data_objects/src/main.cpp
+++ b/endpoints/data_objects/src/main.cpp
@@ -2784,7 +2784,7 @@ namespace
 					{"new-data-checksum", CHKSUM_KW},
 					{"new-data-comments", DATA_COMMENTS_KW},
 					{"new-data-create-time", DATA_CREATE_KW},
-					{"new-data-expiry", DATA_EXPIRY_KW},
+					{"new-data-expiry-time", DATA_EXPIRY_KW},
 					{"new-data-mode", DATA_MODE_KW},
 					{"new-data-modify-time", DATA_MODIFY_KW},
 					//{"new-data-owner-name", DATA_OWNER_KW},