place chrono dep behind feature

ferrtable/Cargo.toml

@@ -4,7 +4,6 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-chrono = { version = "0.4.42", features = ["serde"] }
 derive_builder = { version = "0.20.2", features = ["clippy"] }
 futures = "0.3.31"
 percent-encoding = "2.3.2"
@@ -12,3 +11,7 @@ reqwest = { version = "0.12.23", features = ["json"] }
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.143"
 thiserror = "2.0.16"
+chrono = { version = "0.4.42", features = ["serde"], optional = true }
+
+[features]
+chrono = ["dep:chrono"]

ferrtable/src/types.rs

@@ -1,3 +1,4 @@
+#[cfg(feature = "chrono")]
 use chrono::{DateTime, Utc};
 use serde::Deserialize;
 
@@ -10,9 +11,15 @@ where
     pub id: String,
 
     /// Timestamp of record creation.
+    #[cfg(feature = "chrono")]
     #[serde(rename = "createdTime")]
     pub created_time: DateTime<Utc>,
 
+    /// Timestamp of record creation.
+    #[cfg(not(feature = "chrono"))]
+    #[serde(rename = "createdTime")]
+    pub created_time: String,
+
     /// Contents of record data.
     pub fields: T,