Question on Tune Up Timing

https://israelheaa779.theburnward.com/comfort-experts-ac-repair-north-fort-worth-homeowners-can-count-on

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