The August 2023 issue of “Tools of the Trade” describes the math for finding the date Solar Return angles hit certain degrees or where the angles are on a given date. The methods use the accepted progression rate of the angles of 1.25* per day.
That rate means that your Solar Returns complete most of their work a good bit prior to your next birthday.
In a sense, you will get event previews at that time. And that’s when to start studying the coming year’s Return Charts. To determine this date, figure on 289 days after your birthday.