Ordinary interest rate is calculated based on 360 day year or 30 day month.
Assuming 6% is the annual interest rate. Then,
$5000 * 6% = 300 / 360 = 0.833 daily interest
$91.67 / 0.833 = 110.04 or 110 days.
The total interest amount of $91.67 is the total interest accumulated within 110 days.
