Christmas is Coming in 7 Days: A Mind Puzzle

If a day is a week from now, that makes it 7 days away. A week is 7 days. 7 minus 7 is zero.

If I'm on page 16 in a book, and I have to read to page 23, I could take 23 minus 16 to give me 7. So you'd think I have 7 pages to read. But that would be wrong, because I would have 8 pages to read: page 16, page 17, page 18, page 19, page 20, page 21, page 22, and page 23. So what gives?

So how does the week day math work, and the book page one not?

Well, I have to include page 16 in my counting, because I have to read that page still, and 23-16 minuses that page, so I get one page fewer than I should. 

Whereas for days, the first paragraph was kind of written to get you off-guard. Because it's not written in the same format as the book page paragraph. If I write it in book page format, I would say that today is the 18th. Christmas is the 25th. So 25 minus 18 is... 7. Wait, what? I got the right answer the first time? 

Ah-ha, and that's because there's another difference. When reading pages, we also read page 23. But when counting days, we don't count that last day. On Christmas there are 0 more days until Christmas. On page 23 we still need to read page 23.

So today the 18 there are 7 more days. On Monday there are 6 more days. On Tuesday there are 5 more days. On Wednesday there are 4 more days. On Thursday there are 3 more days. On Friday there are 2 more days. On Saturday there is 1 more day. On Sunday, Christmas, there are 0 more days, because it's arrived. 

My puzzle isn't as good as the missing dollar riddle, but then again, no puzzle is.

"Three guests check into a hotel room. The manager says the bill is $30, so each guest pays $10. Later the manager realizes the bill should only have been $25. To rectify this, he gives the bellhop $5 as five one-dollar bills to return to the guests.

On the way to the guests' room to refund the money, the bellhop realizes that he cannot equally divide the five one-dollar bills among the three guests. As the guests are not aware of the total of the revised bill, the bellhop decides to just give each guest $1 back and keep $2 as a tip for himself, and proceeds to do so.

As each guest got $1 back, each guest only paid $9, bringing the total paid to $27. The bellhop kept $2, which when added to the $27, comes to $29. So if the guests originally handed over $30, what happened to the remaining $1?"  

My secret project for my brothers is almost done. It should be ready a little before Christmas. Secret secret.