This is a question that puzzles many people because, unlike individuals, who must file their taxes to the IRS every year by the same annual deadline (April 15), companies have the benefit of deciding when their fiscal year begins and ends.

There are a couple of things to keep in mind:

  1. Corporations must declare their fiscal year-end (or beginning) when they first form. They can't change it from year to year.
  2. Unlike individuals, corporations must submit quarterly reports of their financial figures to the SEC.

However, the main reason companies choose different fiscal year-ends is that their industries fluctuate at various times, with some showing peak earnings during different seasons than others. Thus, by being able to adjust the timing of their earnings reports, companies can minimize the negative seasonal effects that occur within their specific industries.

For example, a company that has to buy inventory during the summer months probably won't want to report its earnings during this time. This may be because the higher-than-normal inventory purchases will decrease its earnings and create a false image of the company's financial status for that quarter.

Reporting Earnings Quarterly

Each company is required to report earnings on a total of four separate occasions throughout the fiscal year. Three quarterly statements will be filed as 10-Qs, and one annual report with Q4 data within it, will be filed as a 10-K. The SEC requires companies to file 10-Qs no later than 45 days after the end of a quarter. These 10-Ks must be  submitted no later than 90 days following a company's fiscal year-end. 

Some companies choose to postpone their earning announcements for a variety of reasons. In some cases, the audits may not be completed on time to complete the report. Other companies may have inexperienced staff who take longer to complete the task than anticipated. However, there are incidences where accidents, such as computer crashes, technical errors, loss, damage or theft could compromise a company's financial data, making it impossible to report earnings on time. 

When a company postpones announcing earnings, it can sometimes be a signal of a potentially negative earnings surprise, which could impact the share price. Delaying a company's earnings announcement could spur some investors to sell stock, which could further impact share prices. (See also: Surprising Earnings Results, Research Report Red Flags and Types of EPS.)