Update the record with table name and return its value

i have Table with product and dates

Product--21-12-2014--22-12-2014----23-12-2015--------24-12-2015-------25-12-2015

pen----------8--------------4----------6--------------7---------------5

pencil------5--------------9----------5-------------2---------------5

I need to update another table with

product---date---- First_day------------second_day---------third_day--------fourthday-------fifthday

pen------21-12-2014--(8)to be updated------(4)

Challenge is that dates in the second table gets altered. I have many number of tables.

I need to get updated the next 5 days records.

i tried with inner join and cant add date .