PittCo has a policy of paying salaries for contract labor on the 15th of the month following the labor services received. In December 2020, the company paid $15,000 in salaries for labor services received in November 2020. In addition, labor services received in December 2020 were $12,000 and will be paid by the company on January 15, 2021. What adjusting entry will PittCo record on December 31, 2020