For a variety of reasons, some public companies will use a non-standard or non-calendar quarterly reporting system. For example, Walmart's first quarter is February, March, and April; Apple Inc's Q1 is October, November, and December; Microsoft Corporation's Q1 is July, August, and September.

In addition, certain governments use different quarter systems. The first quarter of the United States federal government’s fiscal year is October, November, and December, Q2 is January, February, and March, Q3 is April, May, and June, and Q4 is July, August, and September. State governments may also have their own fiscal calendars.

Sometimes a company may have a non-standard fiscal year to help with business or tax planning. The Internal Revenue Service (IRS) allows companies to choose a “tax year” that is still 52-53 weeks long but does not end in December. H&R Block (HRB) ends its fiscal year on April 30th, which makes sense because that is the end of the busiest part of the company’s year. Releasing your annual report, which may be accompanied by shareholder meetings and additional disclosures after the busiest part of your year will help managers and shareholders make better decisions about the year ahead.

Companies that rely on U.S. government contracts may use September as the end of their fiscal year, and the fourth quarter because that is when they expect new projects to be closed and budget planning from the government to be available. Historically, large technology firms had stronger quarters early in the year, which is why many of them (including Microsoft (MSFT)) have a fiscal year that closes at the end of June.

Some companies have very unusual quarterly systems. Adobe (ADBE) closes their fiscal year on the Friday closest to November 30th. In 2018, November 30th was a Friday, as well as the last day of the month but in 2017, ADBE closed their fourth quarter and the fiscal year on Friday, December 1st, because it was the Friday closest to November 30th.