When Julia and Prof. Stokes read Barnabas's note, they realized that the events of 1897 and 1969 were happening concurrently. It was the same date in 1969!
I thought this was an interesting development as before in the glimpses into the present all we knew was that David was dying and lingering for quite a long time. This is in total contrast to Vickie's trip to the past where she was only missing from the present for a few minutes.
This was an exciting episode with the story running concurrently, and the statement that Barnabas Collins was dead. It did not make sense that Edward could block the passage from the cell in the Old House. I noticed that there was a gas jet lighting the basement of the Old House. When did the family find the time to pipe in gas to a long deserted house and why? And then in the present day the fake old fashioned light bulbs are still in the pole lamps in the foyer