If you ask any accountant which date to choose to start working with Dynamics NAV, they will always answer "January 1". The reason behind this answer is that, for most companies, January 1 is the beginning of their fiscal year. It has advantages, no doubt, but it also has drawbacks. The year has 364 additional days to work, but limiting yourself this much is not worth the hassle and stress.
In this section, we will see the pros and cons of going live at the beginning of a fiscal year versus going live on any other date. With all this information, you should be able to choose the best date in your case and know the consequences of your choice.