The title is a reference to the salute played at military funerals, and at lights out on military installations in the United States. Since Tim's father-in-law was a Colonel in the Army; that title was appropriate for this program. "Taps" was written in 1862 by Union Brigadier General Daniel Butterfield. Within months it was used by both the Union and the Confederates.
As of this episode, both Tim's and Jill's fathers are deceased. Tim's father died when he was just 11 years old. Both of their mothers are still living and as of the final episode both would still be living.