Question on Tune Up Timing

https://lukaseolt009.swiftnestly.com/posts/getting-your-ac-ready-for-summer-with-a-comfort-experts-plan-to-avoid-north-fort-worth-ac-repair-calls

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