Puzzle 021: Twelve Months of Hats

ナゾ０２１　１２月の帽子
ある帽子好きの人が７つの帽子を棚に
並べている。かぶる帽子は月単位で
決まっており、ある年の１月から１１月
まではこのような選び方だってという。
さて、この年の１２月にかぶる帽子は
どれだろう。これだ！と思う帽子を
線で囲んで答えてほしい。
その月のカレンダーを見れば、すぐに
決まるらしいが…。

Google Translate
7 people like that hat one hat shelves. Hat is determined on a monthly basis, a year from January until November of choosing Even like this. Well, this year will be 12 one month hat. This one! Want to answer and I think around the hat line. If you look at the calendar for that month, but now ... 決Marurashii.

Notes on Puzzle
You are given 7 hats, and told that a certain hat lover likes to wear certain hats for each month. Months 1-11 are already marked on the hats, and you have to circle the hat this person would wear in December (Month 12). The puzzle also suggests having a monthly calendar handy will help you solve the clue, which is very, very true. After all, there are seven hats...