Do you want the long version or the short version?
The long version:
A manufactuered date means the date a product comes off the line at a assembly plant (in this case in Japan).
Then the product sits in a distribution warehouse there until the US branch of the company requests it (that could be a day, it could be years depending on the product or part and its demand).
Then it gets put with a huge order, likely in a container, and loaded on a ship in Japan. It then crosses the ocean, ends up at a large US port (sometimes ships have to wait weeks offshore just to access the port if it is busy), the ship is unloaded, the container may or may not be checked by customs, then get taken to the US distributer on the west coast, who puts all those products in a warehouse there until their other regional distribution centers need them, in this case the North East US most likely for B&H. When the regional warehouse needs the product they request to have it transferred with their next order, likely by frieght truck, across the country, and then it gets to the east coast distribution center, finally an authorized dealer like B&H requests the product for their inventory, and the regional distribution center puts it in their next order on a truck to them, and once it gets to B&H, it sits on a shelf until someone wants to buy it.
All that above is not specific to Canon, since I have no idea their exact distribution, but I am probably not far off, and it all assumes the product is for general inventory, and not a rush order or brand new product they are hurrying to market.
Easily the above process can take months or even years, and it really doesn't matter, because they don't change the way they make the lenses (some lenses they sell have been built the same exact way for decades), which is why Canon and MANY MANY other companies have decided to eliminate model year designations from their serial numbers because of "gotta have it now" people who worry if you buy a product that didn't come off the factory floor ten minutes before you opened it, like you are waiting in line for a fresh donut at a Krispy Kreme store with the "hot now" sign on, there must be something wrong with it.
Unlike a donut, the lens is not going to go bad if it sits in its box for a year. If it would it most certainly is not worth its high price tag.
The short version:
Go take some pictures and enjoy your lens.



