A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Date: 2016 Sep 25, 09:19 -0700
Further to Stan's explanation, it is also worth noting that there is an error in the NA which affects sight reduction with a calculator.
The interpolation formula given on page 278 is wrong. It works for all celestial bodies except for the sun. The correct formula for GHA Sun is
GHA = GHA0 + x * 15, where x is computed as stated in the almanac.
The HMNAO has long been aware of the error, but is unwilling to fix it.