A reporting period is the span of time covered by a set of financial statements. The reporting period is typically either for a month, quarter, or year. Organizations use the same reporting periods from year to year, so that their financial statements can be compared to the ones produced for prior years.
The reporting period is stated in the header of a financial report. For example, the income statement header might read, "for the month ended June 30, 20X1," while the balance sheet header might read "as of June 30, 20X1."(accountingtools.com).