Financial reports are based on a company's fiscal year instead of the calendar year. A fiscal year, for accounting purposes, can begin on any day and typically spans two consecutive calendar years.
For example, Apple's fiscal year 2021 (or FY 2021) ran from September 27, 2020, to September 25, 2021. Therefore, its financial report for the first quarter of FY 2021, i.e., 2021Q1, was as of December 26, 2020.
For A-shares, the fiscal year aligns with the calendar year, from January 1 to December 31.
