Best way to use Cialis?

At 55, still get hard, but Cialis does make me harder. Our sex has to be planned: M-F during the mornings after everyone out the house. Im basically taking 20mg on a Sunday evening and it will have an effect on me from Monday morning until almost Friday.

Question is whether it is best to take 20mg once a week, or split and take 10mg on Sunday and another 10mg on Wednesday evening to get me thru T and F?

I mean, does the level dosage influence erection and duration or only erection? I should be able to answer this myself. But everything varies week to week so I dont have the same baseline to compare. Some weeks, she has been out a lot and I am hard from her stories, etc. So I dont know if it is really the Cialis effect or just my brain.
 
All ED drugs depend on underlying physiological-psychological stimulation and feedback to do their job. Neither Cialis or Viagra will cause one to become erect independent stimulation.

For Cialis and generic (Tadalafil), 5mg is a standard daily dose for treating ED and BPH. 10mg - 20mg is typical for single dose ED use, with a 48-72 hour "half life" for most individuals. Getting five days out of a single 20mg dose would be unusual, an outlier. Absent cardiovascular issues, 40mg in 24-hours is safe, but unnecessary for most, especially for those who don't actually have ED.