Question on Tune Up Timing

https://messiahsczr628.lakeviewbrief.com/posts/comfort-experts-on-ac-repair-in-north-fort-worth-when-your-system-runs-but-does-not-cool

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