The "constant" figure is "three" that remains unchanged whether it is "three hours" which is hardly ever "advised" as it is just too less, or "three days" which is the most common, or "three weeks" which I get to read only sometimes and "three years" which is rare and has been "advised" so far.
Surprisingly, this phenomenon is not unique as it is used as an "advisory" figure at posts by someone else also. The connection between the two persons has evaded me so far.
It was "this change" which caught my attention.
I know what cupping is and got to learn of this method of treatment from posts at Qatar Living several months back.