Question on Tune Up Timing

https://elliotvhdc851.rivertonbrief.com/posts/park-glen-ac-repair-in-north-fort-worth-with-comfort-experts

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