inventory database

[Ganolean]

Hi!
Can anyone help me with a formula for my inventory database that will tell it to check the current stock off an item vs the day it actually is and how much stock of an item is supposed to be on hand then return the qty needed to build to that amount.

For example under Neopolitan Crust the current stock is 2 so in the need prepare column it will check that amount vs the days build qty so it would check what day it is and on saturday it says the min is 3 and max is 6 so since the current stock is less then the minimum build qty we must make 4 more to build to max however if the current stock was equal to the minimum build qty you would make nothing

this formula returns and does the math exactly right but because the days change I need to logically test what day it is first and only return the value based on the day
=IF(E7>=P7,0,Q7-E7)