Question on Tune Up Timing

https://troyqbhf798.silverstonebrief.com/posts/smart-thermostat-setup-tips-from-comfort-experts-to-reduce-ac-repair-in-north-fort-worth-homes

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