A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bruce J. Pennino
Date: 2020 Nov 14, 23:57 -0500
I guess I’m missing something here, but why not the moon? The moon must be at least 50 %. Find this in any almanac/source for consecutive days in the month. Depending on time of year, early morning or early evening works fine. If the sky is just right, you can take sight most any time during the day. Given your longitude, find the time from almanac when it is on your longitude. Must start sights at least 20 minutes before and after to find the maximum altitude. Must do some averaging.
If I have completely misunderstood, sorry, in advance.
A 2102d starfinder might help you.