Putting in this post to Invalidate some of my previous hypothesis regarding Flying Stars (Yes, I’ve finish testing).
Flying Stars commonly uses 三元九运 (i.e. 2024 as period 9) and uses 立春 (4 Feb) as cut off point. In 2020, the 20 year cycle, actually ties in with the Conjunction of Jupiter and Saturn (approx 19.85 years). The ancient astrologer may lack science in measurement.
To correct this deviation, the Conjunction of Jupiter and Saturn (Year 2020) + 冬至 (22 Dec) as cut off point.
This method is in relations to the Great Conjunction (五星连珠) in 2040 where Jupiter, Saturn, Mars, Venus, Mercury align with Earth in a straight line.
Period 9 Starts in 2020 (instead of 2024)
Period 1 Starts in 2040 (instead of 2044)
Period 2 Starts in 2060 (instead of 2064)
And, also Invalidating, that Stars are not stagnant, just as Annual Flying Stars changes from year to year, the house chart is not fixated when the resident moves in. Instead, it changes from period to period (i.e. period 8 changes over to period 9), as the period changes, the house chart changes.