all time calculations done within database

server/step_manager.go

@@ -93,10 +93,6 @@ func (sm *StepManager) SaveTripState() {
 }
 
 func (sm *StepManager) saveTripStateLocked() {
-	fmt.Printf("[StepManager] Saving trip state for %s: StartTime=%v (%s), LastSync=%v (%s)\n",
-		sm.userID, sm.tripState.StartTime, sm.tripState.StartTime.Location(),
-		sm.lastSyncTime, sm.lastSyncTime.Location())
-
 	_, err := db.Exec(`
 		INSERT INTO trips (user_id, start_date, start_time, start_day_initial_steps, previous_total_steps, target_total_steps, last_sync_time, next_sync_time)
 		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
@@ -248,6 +244,20 @@ func (sm *StepManager) performSync(interval time.Duration) {
 	sm.lastSyncTime = time.Now()
 	sm.nextSyncTime = time.Now().Add(interval)
 
+	// Save final state with explicit NOW() for last_sync_time to ensure DB consistency
+	// next_sync_time is also calculated in SQL relative to the same NOW()
+	_, err = db.Exec(`
+		UPDATE trips SET 
+			last_sync_time = NOW(),
+			next_sync_time = DATE_ADD(NOW(), INTERVAL ? SECOND),
+			previous_total_steps = ?,
+			target_total_steps = ?
+		WHERE user_id = ?
+	`, interval.Seconds(), sm.previousTotalSteps, sm.targetTotalSteps, sm.userID)
+	if err != nil {
+		fmt.Printf("Error saving sync completion: %v\n", err)
+	}
+
 	fmt.Printf("Sync Complete. Total Trip Steps: %d\n", sm.targetTotalSteps)
 }