A quarter is a three-month period on a company's financial calendar that acts as a basis for periodic financial reports and the paying of dividends. A quarter refers to one-fourth of a year and is typically expressed as Q1 for the first quarter, Q2 for the second quarter, and so forth. For example, a quarter is often shown with its relevant year, as in Q1 2021 or Q121, which represents the first quarter of the year 2021.