It hangs from, what you play: RuB has other, more real dates. There you can get only at the 11th flottilla, july 1944, but the base-beeing-time is as I know, 256 day.
I will modify it to 180 day, and maybe, if you pay 40.000 renown, you can get it in may 1944.
That is, in my oppinion between historical and realistic, and gaming fun.
