Chart with moving range

Hi, I want to do a tendency chart using values that are added every day and I want to avoid changing ranges. The issue here is that I would like to have the option to show an specific range, in this case of dates and their respective values from the whole data base so the chart would show only those values, can be a range from the begining, from the middle or the end of the data base, no more no less......

Any help would be really appreciated......

Carlos