Hi juzdive,
As I am sure you know, the no-fly time will very much depend of the type of diving you intend to do but I suspect a full 24 hours may be sufficient if you do not do any serous technical dives but 20 dives will load your slower tissue compartments considerably.
As a memebr of this forum you must know, from earlier threads, that it takes 24 hours to completely desaturate from helium and two and a half days, that is 63.5 hours, to completely desaturate the slowest tissue compartments of nitrogen. So you are still effectively decompressing on the Tuesday evening if your last dive was on the previous Sunday.
As I am sure you also know most dive computers provide no fly times after diving - not much use for planning a holiday I know!
I am sorry I cannot answer your question myself but I have posted this as would like to know what state of saturation computer alogorithms use before they consider it is safe to fly. I am sure there must be an accepted standard.