@David *******
The requirement for how long the funds need to be in the bank isn’t very clear—it seems to vary depending on the embassy and even the time of year you apply. In short, it keeps changing.
I’ve had the funds in my account for just over two months now. To be on the safe side, I was thinking of adding another bank balance to strengthen the application, in case the embassy expects the funds to have been there for more than three months. If I knew for sure that three months was the fixed requirement, I’d simply wait until I reached that mark before applying.