Drink 7 to 10 days after opening?

Is this label telling the consumer that it is best to consume the drink 7 to 10 days after opening it?

I know what they are getting at, but I feel like it should say "Best if consumed within 7 to 10 days of opening". Is my suspicion correct?

This is what I perceive like the label is really saying

    |----|----|----|----|----|----|----|----|----|----|
       1    2    3    4    5    6    7    8    9   10
   (Opened)                        (Best consumed here)

No. You are wilfully parsing it as though "7 - 10 day" is an interval to which within applies. But within does not take an implicit interval like that. You could say "within the period 7 - 10 days", but that's the only way I can see to get the meaning you want.

Which leaves the alternative (and clearly intended) parsing within x days after opening, where x is specified loosely.

The "Within" portion of the phrase is intended to eliminate the interpretation that you are trying to impose on it.

opened
0---1---2---3---4---5---6---7---8---9---10
(within 7 days .............)    
(within 10 days .........................)
(within 7-10 days ..........?????????????)

The extended portion of the range covered by . is definitely good; the portion covered by ? is probably good, but not guaranteed.

The "after opening" is probably there to frustrate the pedants who would insist that "within 7-10 days of opening" includes a total of 14-20 days:

                               open
10--9--8--7--6--5--4--3--2--1--0--1--2--3--4--5--6--7--8--9--10
          (within 7 days of ........................)
                               (within 7 days after )