For Horngren's Accounting chapter 9, problem 30, accounting for uncollectible accounts (aging-of-receivables method), credit card sales, notes receivable, and accrued interest revenue. On November 16, loaned $22,000 cash to Creed Company receiving a 90-day, 12% note. On December 31, accrued the interest on the Creed Company note. Interest revenue= $22,000*12%*45/360 to get $330. Why is the fraction 45/360?