Final answer:
The date at the bottom of an unqualified audit opinion is the audit report date, marking the last day the auditor gathered evidence for their opinion on the financial statements.
Step-by-step explanation:
The date at the bottom of an unqualified audit opinion refers to the audit report date. This is a significant date as it signifies the last day on which the auditor performed audit procedures and gathered sufficient appropriate audit evidence to form an opinion on the financial statements. After this date, the auditor is no longer responsible for considering the financial statements and any subsequent events, unless there is a material subsequent event that requires disclosure or adjustment to the financial statements. It is important to note that the audit report date should not be confused with the date the financial statements are issued or the period-end date of the financial statements.