For USA taxes, if I have two choices of either working from January 2015 to January 2016 and not work for a year, versus working from June 2015 to June 2016, and not work for a year, isn't the second choices a lot better for taxes, because the wages are more evenly divided between 2 years?

That is because (1) if the wages is all within a calendar year, then the tax bracket is higher -- for every dollar I earn, 45 cents can go to taxes, versus if the wages is divided into 2 years, then for every dollar I earn, it might be 30 cents that will go to taxes. The other reason is that (2) if there is any type of deduction, such as mortgage deduction, then if the wages is divided into 2 years, then the mortgage deduction can apply towards year 1 and year 2, versus if the wages are mostly in 1 calendar year, then the mortgage deduction can apply toward year 1, but is virtually useless in year 2.

It is a little bit strange that just choosing which months you work can make quite a bit of difference, instead of if our income is taxed at a 30% simple rate, then there is very little rules, as opposed to, the more rules there are, the more ways there are to get around it.