A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Fleming
Date: 2015 Oct 10, 10:17 -0700
Sorry about being crptic.
If Latitude and Declination are near to each other, then the sextant altitude approaches 90 degrees at meridian transit. Further this means that the altitude changes more as your sight time departs from actual meridian transit, so knowing exaclty when MT is becomes important.
Table 29 and Table 30 in Bowditch quantify the importance of knowing exact time while also allowing one to still use a MT sight analysis for sights not taken at MT, if not too far from MT.