diff --git a/modeling-cmds/Cargo.toml b/modeling-cmds/Cargo.toml
index cfcae264..3054f96f 100644
--- a/modeling-cmds/Cargo.toml
+++ b/modeling-cmds/Cargo.toml
@@ -12,7 +12,7 @@ license = "MIT"
 
 [dependencies]
 anyhow = "1.0.97"
-chrono = "0.4.39"
+chrono = { version = "0.4.39", features = ["serde"] }
 cxx = { version = "1.0", optional = true }
 data-encoding = "2.8.0"
 enum-iterator = "2.1.0"
diff --git a/modeling-cmds/src/datetime.rs b/modeling-cmds/src/datetime.rs
index 139e365e..f213edc9 100644
--- a/modeling-cmds/src/datetime.rs
+++ b/modeling-cmds/src/datetime.rs
@@ -1,5 +1,8 @@
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+
 /// A wrapper for chrono types, since we need to impl Value for them.
-#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Default)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash, Default, Deserialize, Serialize, JsonSchema)]
 pub struct DateTimeLocal {
     value: chrono::DateTime<chrono::Local>,
 }
diff --git a/modeling-cmds/src/format/fbx.rs b/modeling-cmds/src/format/fbx.rs
index f1411d19..e0da67d3 100644
--- a/modeling-cmds/src/format/fbx.rs
+++ b/modeling-cmds/src/format/fbx.rs
@@ -30,10 +30,6 @@ pub mod export {
         pub storage: Storage,
 
         /// Timestamp override.
-        ///
-        /// This is intended for local integration testing only; it is not provided as an option
-        /// in the JSON schema.
-        #[serde(skip)]
         pub created: Option<DateTimeLocal>,
     }
 
diff --git a/modeling-cmds/src/format/step.rs b/modeling-cmds/src/format/step.rs
index 1f6d61dc..9f25d973 100644
--- a/modeling-cmds/src/format/step.rs
+++ b/modeling-cmds/src/format/step.rs
@@ -3,6 +3,7 @@ use schemars::JsonSchema;
 use serde::{Deserialize, Serialize};
 
 use crate::coord;
+use crate::datetime::DateTimeLocal;
 
 /// Import models in STEP format.
 pub mod import {
@@ -38,12 +39,9 @@ pub mod export {
         ///
         /// [KittyCAD co-ordinate system]: ../coord/constant.KITTYCAD.html
         pub coords: coord::System,
+
         /// Timestamp override.
-        ///
-        /// This is intended for local integration testing only; it is not provided as an option
-        /// in the JSON schema.
-        #[serde(skip)]
-        pub created: Option<chrono::DateTime<chrono::Utc>>,
+        pub created: Option<DateTimeLocal>,
     }
 
     impl Default for Options {