A calendar quarter is a period of three consecutive months, and there are four quarters per calendar year. The quarters of the calendar year are January, February, March (quarter 1); April, May, June (quarter 2); July, August, September (quarter 3); and October, November, December (quarter 4.)
A calendar quarter is differentiated from a fiscal quarter. A calendar quarter corresponds to the calendar year. The first days of each calendar quarter are always January 1, April 1, July 1, and October 1. Fiscal quarters are determined by the specific fiscal year that a business uses, usually based on factors such as taxes, reporting requirements and whether the business needs to align its fiscal activities with other organizations, such as government or academic institutions.