Quarter (Q1, Q2, Q3, Q4)
A three-month period on a financial calendar that acts as a basis for the reporting of earnings and the paying of dividends.
Investopedia Commentary
Quarters are important because all public companies must report their results on a quarterly basis.
You'll hear the following abbreviations:
Q1 - January, February, and March
Q2 - April, May, and June
Q3 - July, August, and September
Q4 - October, November, December
For example, if earnings per share were $1.50 in Q1, this means earnings were $1.50 for the period of January, February, and March.
See also: Dividend, Earnings, GAAP, Public Company, Quartile