NavList:

List:

I can add a small data point to this discussion, showing time-keeping practice on a ship taking Irish immigrants from Liverpool to Boston in 1845.  One passenger was my great-grandfather, age 22, who kept a detailed journal that I now have.  Here he records the start of the voyage:   

"Sunday, July 13th, ’45 — Begins pleasant.  Wind south.  At 3 a.m. weighed anchor.  Made all sail with the steam tug Powerful and proceeded to sea at 7 a.m.  Discharged pilot and tug; set all std. sails on our voyage with a crew of 13, including officers, and 105 passengers.  At 12 meridian wind hauled to the west in std. sails & braced sharp by the wind.... So ends the day of 12 hours — civil acct. —

"Ship Persia, Richard Johnson Master —

"Monday, July 14th, 1845.  Begins with fine, moderate breeze from the west.  All sail set by the wind at 2 p.m.  Tacked ship to the S.W. at 9 Do.  Tacked to the west.  Isle of Man bearing N.N.W., dist. 6 miles.  Middle part fresh; breeze from N.N.W.; all sail set.  At 8 a.m. Holy Head bore east by compass, dist. 16 miles.  Latter part fine.  Breeze & clear weather.  Stowed anchor —.  Passengers all seasick.  Steward remains off duty.  E. wds., pleasant.  Variation 2¾ points westly; 1 day out."

And here is a typical entry mid-Atlantic, showing how the sea day starts with p.m. hours and finishes in the a.m.:

"Saturday, Augt. 2nd, 1845.  Comes in moderate from the S.E., all sail set at 7 p.m. in all std. sails and brows braced sharp by the wind.  Middle part light wind from the S.W.  At 2 a.m. tacked; the wind from N.W. tight braced round yards; ship’s head to the W.S.W.  Latter part the same.  All sail set by the wind.  Saw several sail standing to the eastward.  Ends moderate.  Lat. obs. 45 25 N.  Long. 42, 18, 9:40 a.m.  20 days out."

Finally they reach Boston harbor:

"Saturday, Augt. 23rd, 1845.  Comes in with light breezes from the southward.  All possible sail set at 9 p.m.  Made Boston Light bearing W. by N. by compass at 10 Do.  Laid the main topsail to the mast.  Thick fog.  Middle part the same.  At 4 a.m. made sail for to run in at 7 a.m.  Came to anchor at Boston Lighthouse.  Thick fog at 8 Do. Got a Boston pilot & weighed anchor.  Made all sail on our way towards Boston ...came to anchor abreast of Long Wharfe.  At 1 p.m. weighed anchor & hauled into Rowes Wharfe.  Made fast the ship.  Discharged the crew.  Captn. gone home.  Latter part showery attended with thunder & lightening.  So ends the day of 36 hours & passage of 41 days...."

Roger