Question of Accounting Concept - fiscal

There are most of firms prepare income statement for calendar years, but some of the firms use fiscal years. We know if this company’s share in the stock market, they needs to issue the last years income statement and other reports on certain month, but if the company follow the fiscal year, how can they provide these reports as the companys follow calendar years. I mean goverments request the report issused date must be base on calendar year, is it?

Does any one know what I’m talking about? anyways, thanks all your advice.