Question on Tune Up Timing

https://zionnfzt160.slatecurrent.com/posts/warm-air-on-the-first-hot-day-means-north-fort-worth-ac-repair-and-a-call-to-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