Because the PSP will have a stock count at the end of the year on December 29, 2015 and will stop the production of the raw materials received and shipped between the dates 28-December 30, 2015, I.
The PSP will have the stock at the end of the year on December 29, 2558 and will cease production as the raw material and shipping it 28-30 December 2558.
Because PSP are counting inventory at the end of the year. On the day 29 December 2558 and will want to stop production, raw material and shipping during the 28-30 December 2558.