what are the quarters in a calendar year
Calendar year
First quarter, Q1: 1 January – 31 March (90 days or 91 days in leap years)
Second quarter, Q2: 1 April – 30 June (91 days)
Third quarter, Q3: 1 July – 30 September (92 days)
Fourth quarter, Q4: 1 October – 31 December (92 days)