There are two ways of doing this.
1) Add 3 seconds to the DateTime before you get its TimeOfDay:
TimeSpan RecordingStartTime = DateTime.Now.AddSeconds(3).TimeOfDay;
2) Add a new TimeSpan to the TimeSpan:
TimeSpan RecordingStartTime = DateTime.Now.TimeOfDay;
Reading the documentation for the TimeSpan object should have given you this information.
/- Sam Judson : Wrox Technical Editor -/