What would you do to this code to make it more maintainable and testable?
```cs
	public static class Saver
    {
        public static void Save(string contents)
        {
            var day = DateTime.Now.DayOfYear;
            var machine = Environment.MachineName;
            var file = day + "_" + machine + ".txt";
            File.WriteAllText(file, contents);
        }
    }
```