Final answer:
The most commonly adopted annual accounting period (fiscal year) by businesses is January 1 to December 31, aligning with the calendar year for simplicity and consistency in accounting and tax reporting practices.
Step-by-step explanation:
The annual accounting period (fiscal year) most commonly adopted by businesses is January 1 to December 31. This period aligns with the calendar year and is widely used across various industries for accounting and tax purposes.
Various calendars throughout history have attempted to keep track of time, including the Metonic calendar and the Persian calendar. However, in the modern context, the Gregorian calendar has been widely adopted, which also serves as the basis for the traditional fiscal year used by most businesses today.
The federal budget, on the other hand, operates on a different fiscal year, running from October 1 to September 30 of the following year. This timeline is used to manage the budget, which includes determining the annual budget deficit or surplus, based on tax revenues and spending.