I've been playing on and off since 2008 and I'm around October 1943 with my latest career.
Early on, I only played one career and things were moving along but for some insane reason I decided to play multiple careers in different flotillas. Now I have one in the Med, a Black Sea career, and a couple out of France, and one out of Norway at various times during the war. I wanted to experience the different feel for the various flotillas.
I play one flotilla until I die/retire or am just in the mood to go to one of my other flotilla careers.
On all my careers, when I die/retire, I start a new career at about the same timeframe. I don't go back to 1939. I'd never see the end. I want to experience the whole war.
So, at this rate I may see 1945 about the time I'm retired and my brain is too addled to even play.
I also have been playing SH4 as the mood strikes. That throws a wrench into the whole works.