Question on Tune Up Timing

https://daltonzdfs706.theglensecret.com/signs-your-ac-needs-repair-in-north-fort-worth-before-you-call-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