C#

        Main()
        {
            LaunchThreads(syncNodes); //Usually 2 XML nodes with some basic info like "period" and connection strings etc.
            //Thread.Sleep(-1); //With threads still alive I realised this line wasn't needed as the program will still be executing until all threads are dead (or if published as a task bar type windows app - the app is closed by the user)
        }

        static void LaunchThreads(XmlNodeList syncThreads)
        {
            foreach (XmlNode threadSetting in syncThreads)
            {
                Sync syncThread = new Sync(threadSettings);
                Thread t = new Thread(new ThreadStart(syncThread.Start));
                t.Start();
            }
        }
    }

    public class Sync
    {
        private XmlElement settings; //stores the info for the data transfer, period, connections etc.
        private int period;
        public Boolean interrupt

        public Sync(XmlElement syncSettings)
        {
            settings = syncSettings;
            interrupt = false;
            period = Convert.ToInt16(settings.GetAttribute("period").ToString())*60000;
        }

        public void Start()
        {
            while(!interrupt)
                {
                Execute();
            Thread.Sleep(period); 
                }
        }

        private void Execute()
        {
            //Do the data transfer using the "settings" XmlElement to define which database to connect to etc.
            //I have tried the code with and without the contents of this methods and the results in the private bytes are the same
        }
}