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Re: How to calculate daily advance of GHA Aries?
From: Frank Reed
Date: 2025 Aug 16, 12:39 -0700
From: Frank Reed
Date: 2025 Aug 16, 12:39 -0700
Start with some relatively arbitrary date at 00:00:00 UT, reasonably close to the date of interest. Get GHA Aries for that date from your favorite reliable source.
For any later date and UT, calculate the number of days since the arbitrary starting date.
Add 0.985648°×days, and
Add 1.002738°×(15×hrs + min/4 + sec/240) for hours, minutes, seconds of UT on that later date.
Frank Reed
