Definitely not a year. 4-6 months tops if you play a few hours a day. It used to take a year (if not more) back when Silver was the standard account. At the base level, you are currently earning what used to be premium (minus 1k). Buying premium now gives you an additional 60% over that.

took me 9 months to get to RM BB6 but in that time I also grinded up to KM ss4 and KM bb4. Without premium. 

You can grind from lvl 1 to 120 in one month with 200% exp boost

It also depends on the attack you manage to get in a game. 
It's easier to get RM BB6 faster, because it's more easy to play. It took me 6 years to get a KM BB and CV6. But it took me a little while, 1.5 year, to get US & RM BB5s (stopped lvling because I found BB5s more fun, won't take me that long to get the 6s with those nations anyway) and I am now also close to my third (IJN) BB5. The first 6 is for most players hard to get, simply because of lose of motivation.

I hope you have the Hyuga, it will make it a bit easier to get massive attacks. Try to get 100k +
When you find it hard to get 100k +, then look at the better players, especially at those who play IJN. Most important advice I can give you is to keep it fun, because it's a game. :P

Good luck ^^

P.S.: I play a couple hours per week, it kinda depends on school etc. I have a premium account. So it should be easy to get it within a year.

Took me a bit less then 6 months to get Amagi. Once u can use Fuso, ull probably go faster, since that is one nasty ship.
I found Nagato dissapointing, Yamato average compared to Iowa from my previous bb grind. When ur used to the SY though, it is one epic ship! So keep it up till SY and then you'll probably end ur grind, cause its a fun ship:)