diff --git a/Cargo.toml b/Cargo.toml
index 60d9fe2..b788ba5 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -17,7 +17,7 @@ reqwest-middleware = "*"
 rand = {version="*", default_features = false, features = ["std", "std_rng", "getrandom"]}
 
 # to perform time-based calculations
-time = {version="*", default_features = false, features = ["formatting", "parsing", "macros", "serde"]}
+time = {version="*", default_features = false, features = ["formatting", "parsing", "macros", "serde", "serde-well-known"]}
 
 # compute distances between geo-points
 geoutils = {version="*", default_features = false}
diff --git a/src/icao_to_trace.rs b/src/icao_to_trace.rs
index 9e7e4e0..1fb84d9 100644
--- a/src/icao_to_trace.rs
+++ b/src/icao_to_trace.rs
@@ -5,7 +5,7 @@ use reqwest::{self, StatusCode};
 use reqwest_middleware::ClientBuilder;
 use reqwest_retry::{policies::ExponentialBackoff, RetryTransientMiddleware};
 use time::Date;
-use time::PrimitiveDateTime;
+use time::OffsetDateTime;
 
 use super::Position;
 use crate::{fs, fs_s3};
@@ -174,7 +174,7 @@ pub async fn positions(
             trace.into_iter().filter_map(move |entry| {
                 let time_seconds = entry[0].as_f64().unwrap();
                 let time = time::Time::MIDNIGHT + time_seconds.seconds();
-                let datetime = PrimitiveDateTime::new(date.clone(), time);
+                let datetime = OffsetDateTime::new_utc(date.clone(), time);
                 let latitude = entry[1].as_f64().unwrap();
                 let longitude = entry[2].as_f64().unwrap();
                 entry[3]
diff --git a/src/lib.rs b/src/lib.rs
index 1f46689..a9fe062 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -31,7 +31,8 @@ pub use private_emissions::*;
 /// A position of an aircraft
 #[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
 pub struct Position {
-    datetime: time::PrimitiveDateTime,
+    #[serde(with = "time::serde::rfc3339")]
+    datetime: time::OffsetDateTime,
     latitude: f64,
     longitude: f64,
     /// None means on the ground
@@ -65,7 +66,7 @@ impl Position {
         self.altitude.unwrap_or(0.0)
     }
 
-    pub fn datetime(&self) -> time::PrimitiveDateTime {
+    pub fn datetime(&self) -> time::OffsetDateTime {
         self.datetime
     }
 
diff --git a/tests/it/main.rs b/tests/it/main.rs
index 009ab65..841d0fc 100644
--- a/tests/it/main.rs
+++ b/tests/it/main.rs
@@ -86,6 +86,8 @@ async fn ads_b_lost_on_ground() -> Result<(), Box<dyn Error>> {
     Ok(())
 }
 
+/// Verifies that condition 2. of `M-4` is correctly applied.
+/// https://globe.adsbexchange.com/?icao=459257&showTrace=2023-12-17
 #[tokio::test]
 async fn case_459257_2023_12_17() -> Result<(), Box<dyn Error>> {
     let legs = legs(date!(2023 - 12 - 17), date!(2023 - 12 - 20), "459257", None).await?;