Rates are set by fiscal year, effective October 1 each year. Find current rates in the continental United States ("CONUS Rates").
Under the cash method you report income in the year it is actually received. If you receive a check that bounces, don't include it in gross income. If you redeposit a bounced check and it clears the bank, include it in income at that time.
You're a sole proprietor on a calendar year (year ends December 31). On December 27, 2020 you receive a $500 check from a customer and deposit it. On December 31, 2020 the check bounces. Do not include the $500 in your 2020 income.
During January 2021 you redeposit the $500 check that bounced and it clears the bank. Include the $500 in your 2021 income.