First Patek — inquired a few months ago expecting quite a wait but got the call faster than anticipated. Weighs nothing, fits every strap type. Highly recommended for all considering the brand!
(It’s also nice having a watch that reminds me when it’s Wednesday, my dudes.)
It is indeed the week number. Some cultures (such as mine, Danish) refer to e.g. week 37 a lot more when making plans.