diff --git a/src/system.rs b/src/system.rs
index 2ebeefd..587883a 100644
--- a/src/system.rs
+++ b/src/system.rs
@@ -39,8 +39,18 @@ pub fn ntp_service_toggle(start: bool) {
 
 pub fn calculate_target_time(frame: &LtcFrame, config: &Config) -> DateTime<Local> {
     let today_local = Local::now().date_naive();
-    let ms = ((frame.frames as f64 / frame.frame_rate) * 1000.0).round() as u32;
-    let timecode = NaiveTime::from_hms_milli_opt(frame.hours, frame.minutes, frame.seconds, ms)
+    // Calculate total milliseconds including fractional frames
+    let total_ms = ((frame.hours as f64 * 3600.0 + 
+                    frame.minutes as f64 * 60.0 + 
+                    frame.seconds as f64 + 
+                    frame.frames as f64 / frame.frame_rate) * 1000.0).round() as u32;
+    
+    let seconds = total_ms / 1000 % 60;
+    let minutes = (total_ms / 60000) % 60;
+    let hours = (total_ms / 3600000) % 24;
+    let ms_component = total_ms % 1000;
+    
+    let timecode = NaiveTime::from_hms_milli_opt(hours, minutes, seconds, ms_component)
         .expect("Invalid LTC timecode");
 
     let naive_dt = today_local.and_time(timecode);