Period of Report vs. Filing Date

The period of report is the date an SEC filing speaks to — the end of the fiscal year or quarter a 10-K or 10-Q covers, or the date of the event an 8-K reports — while the filing date is the day the document actually reached the SEC. The gap between them can run weeks or months.

Mixing them up means misreading financial data in time: a quarter's results describe the business as of its period end, but the market only learned them on the filing date.

Full guide: SEC Filing Deadlines by Filer Status: The Calendar

The cover of Form 10-K names the fiscal year ended, the cover of Form 10-Q names the quarterly period ended, and Form 8-K carries a "Date of Report," defined as the date of the earliest event reported. The filing date is when the SEC receives the submission; the Section 16 rules, for example, state outright that an insider report counts as filed on the date the Commission receives it.

The rules put a ceiling on the gap. A 10-K is due 60, 75, or 90 days after fiscal year end for large accelerated, accelerated, and other filers, and a 10-Q is due 40 or 45 days after quarter end. An 8-K generally follows its triggering event within four business days, and an insider's Form 4 is due within two business days of the trade. A company that misses a 10-K or 10-Q deadline can file Form 12b-25 and still be treated as timely if the report follows within 15 calendar days for an annual report, or five for a quarterly one — widening the gap further.

For investors, the distinction matters in any backtest or event study. Using period-end dates as if the data were known on that day introduces look-ahead bias, because the numbers were not public yet. It also matters for amendments, which carry the original period of report but a later filing date. GeminIQ organizes financial statement history by period end date and shows each report's actual filing date in its list of filings, so both dates are available.