Some misconceptions in this thread on how inventory turnover is calculated.
It is (commonly) calculated as COGS / Average Inventory.
Let's say your COGS for a Macbook is $500. You buy material on Jan 1 to make it, assemble on Jan 2, and ship Dec 31. Your turnover is $500 / $500 = 1 for the year.
If you buy parts to make 2 Macbooks on Jan 1 your inventory turnover would be 0.5 ($500 / $1000).
This accounts for unused A5 chips in stock (or anything else unused), and online sales don't count as "0 days".