Question on Tune Up Timing

https://felixutvt287.unionquill.com/posts/ac-repair-for-heritage-homes-by-comfort-experts-in-north-fort-worth-2

Question on Tune Up Timing Does anyone know if spring or fall is better for a tune-up? Not sure when it makes the most sense for an older system in Summerfields, since the AC works hardest in summer but the furnace matters in winter