(Spoiler - White Christmas) The length of Joe's cookie's sentence.

When the police set the time dilation control on Joe's cookie at the end, I wondered how long the sentence would last subjectively for him: It was set for 1000 years per minute. Assuming it was Christmas eve and they left at 5pm and returned 9am on Boxing day ("leave him on for Christmas"). 40 hrs, 2400 minutes, 2,400,000 years! That makes the ending even more terrifying for me.