diff --git a/iox_time/src/lib.rs b/iox_time/src/lib.rs
index 9cc1e5be03..d5de3dea58 100644
--- a/iox_time/src/lib.rs
+++ b/iox_time/src/lib.rs
@@ -82,14 +82,6 @@ impl Time {
         Self(Utc.timestamp_millis(millis))
     }
 
-    /// Makes a new `DateTime` from the number of non-leap milliseconds
-    /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp").
-    ///
-    /// Returns None if out of range
-    pub fn from_timestamp_millis_opt(millis: i64) -> Option<Self> {
-        Some(Self(Utc.timestamp_millis_opt(millis).single()?))
-    }
-
     /// Makes a new `Time` from the number of non-leap seconds
     /// since January 1, 1970 0:00:00 UTC (aka "UNIX timestamp")
     /// and the number of nanoseconds since the last whole non-leap second.
@@ -324,8 +316,6 @@ mod test {
         assert!(chrono::Duration::from_std(duration).is_err());
         assert!(time.checked_add(duration).is_none());
         assert!(time.checked_sub(duration).is_none());
-
-        assert!(Time::from_timestamp_millis_opt(i64::MAX).is_none())
     }
 
     #[test]
diff --git a/write_buffer/src/kafka/mod.rs b/write_buffer/src/kafka/mod.rs
index 6623e1f622..45d672d5d5 100644
--- a/write_buffer/src/kafka/mod.rs
+++ b/write_buffer/src/kafka/mod.rs
@@ -191,18 +191,10 @@ impl WriteBufferStreamHandler for RSKafkaStreamHandler {
                 sequence_number: SequenceNumber::new(record.offset),
             };
 
-            let timestamp_millis =
-                i64::try_from(record.record.timestamp.unix_timestamp_nanos() / 1_000_000)
-                    .map_err(WriteBufferError::invalid_data)?;
+            let timestamp_nanos = i64::try_from(record.record.timestamp.unix_timestamp_nanos())
+                .map_err(WriteBufferError::invalid_data)?;
 
-            let timestamp = Time::from_timestamp_millis_opt(timestamp_millis)
-                .ok_or_else::<WriteBufferError, _>(|| {
-                    format!(
-                        "Cannot parse timestamp for milliseconds: {}",
-                        timestamp_millis
-                    )
-                    .into()
-                })?;
+            let timestamp = Time::from_timestamp_nanos(timestamp_nanos);
 
             let value = record
                 .record