There are plenty of on-line calculators but find that this is much more useful:
https://goes.gsfc.nasa.gov/text/goeshori.xls
To get the true bearing enter
in a spare cell.
I've uploaded a copy in case it disappears.
https://goes.gsfc.nasa.gov/text/goeshori.xls
To get the true bearing enter
Code:
=180-B6I've uploaded a copy in case it disappears.