there are 2 cases in which present perfect are used
an action continue until present. this case is easy
second case is that the action finish at a point in past but its time frame continue until present. this mean the context of the finished action cover a period from a past point of time to present. this case is harder for us.
I have cleaned the floor
at present, the speaker say above sentence. the cleaning finished in the past but its context or in other words, its time frame continue until present. we should not confused simple past this case of present perfect. this case must have time indicator which is unfinished. we can not use finished time indicators such as yesterday, or last year.
our problem dose not involve the second case