Accounting Standards
In order that financial statements report financial performance fairly and consistently, they are prepared according to widely accepted accounting standards. These standards are referred to as Generally Accepted Accounting Principles, or simply GAAP. Generally Accepted Accounting Principles are those that have "substantial authoritative support".
Accrual vs. Cash Method
Many small businesses utilize an accounting system that recognizes revenue and expenses on a cash basis, meaning that neither revenue nor expenses are recognized until the cash associated with them actually is received. Most larger businesses, however, use the accrual method.
Under the accrual method, revenues and expenses are recorded according to when they are earned and incurred, not necessarily when the cash is received or paid. For example, under the accrual method revenue is recognized when customers are invoiced, regardless of when payment is received. Similarly, an expense is recognized when the bill is received, not when payment is made.
Under accrual accounting, even though employees may be paid in the next accounting period for work performed near the end of the present accounting period, the expense still is recorded in the current period since the current period is when the expense was incurred.