I'm not an accountant, but I do have a Canadian corporation with a June 30th year end. What I have found is that there is no tax advantage in that you will not somehow end up paying less tax than if you had chosen any other year end date, but there is a timing advantage in that the corporation's taxes are due 6 months after you file while your personal taxes are due in April of the following year. I have found that this has helped me plan out my tax payments a bit better, but that's about it.
There is an advantage to choosing carefully so that you can defer taxes.
My corporation has a year end at the end of February. In January of year X, I can make a ledger entry to transfer income to myself (personally) which will have the tax payable in April of year X+1. The corporation, noting the payment as an expense, will not have to pay tax on it that year, so I've managed to defer the payment for about a year.
Theoretically, this can be chained so that deferment is done continuously since it doesn't matter when the actual money transfer takes place. So if you had 2 corporations, you could have one do the transfer in January, the next do it in February, etc... eventually ending up in your hands.
The catch with this is that unless you can justify the existence of the additional corporations for reasons other than taxation, you can get taxed immediately anyhow, since setting up such structures for tax avoidance means that Revenue Canada can just ignore the structure.
As such, anything beyond a single corporation transferring to yourself is unlikely to work, and if you're earning enough, then you should get an accountant who can help you with tax planning based on your particular situation.