You don't know what day you will arrive? Simple math as in hrs per day divided into time to go should answer your question. I mean if it is a very long journey, math and refiguring the actual date of arrival may be one of the more interesting things to do. Manuel plotting, every hr with position updates, sea state, wind
speed and direction along with SOG are how we do coastal cruising. We feel it is impt to stay personally engaged, and alert instead of just reading data.