Q1 refers to Quarter 1 (Jan to Mar), Q2 refers to Quarter 2 (Apr to June), Q3 refers to Quarter 3 (July to Sept), Q4 refers to Quarter 4 (Oct to Dec). Rolling three-month estimates are calculated by comparing GDP in a three-month period with GDP in the previous three-month period. For example, GDP in January to March compared with the previous October to December.GDP increased by 0.5% in Quarter 1 (Jan to Mar) 2019, up from the 0.2% increase in Quarter 4 (Oct to Dec) 2018. The strength in quarterly growth is in part due to the low December monthly growth in the base period, which makes the current period look ... (full story)