Question on Tune Up Timing

https://shanefadk435.inkharbory.com/posts/why-north-fort-worth-homeowners-choose-a-local-company-like-comfort-experts-for-ac-repair-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