Question on Tune Up Timing

https://stephenxpta941.wordcanopy.com/posts/comfort-experts-on-replacing-your-ac-when-north-fort-worth-ac-repair-no-longer-makes-sense-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